Pregnancy Symptoms Week By Week

Pregnancy can be one of the most exciting times in a woman’s life, however, it can also be exhausting, scary, and full of uncertainty. As your body transitions through the various stages of pregnancy you will undergo physical, mental and hormonal changes. For many parents and parents-to-be these upcoming challenges can feel overwhelming.

The symptoms of pregnancy are different for everyone, even if you have been pregnant before it is unlikely that you will have the exact same experience. Understanding how your body is changing and what you are feeling can help relieve unnecessary worry and stress.

This article will give you an overview of what symptoms you may experience, how you can help yourself to feel your best and when it is important to contact your healthcare provider. 

How ‘pregnant’ are you?

Pregnancy, also referred to as gestation, lasts around 40 weeks.¹ We calculate the number of weeks you’re pregnant based on the first day of your last menstrual period. We do not calculate gestation from the date of conception (when sperm fertilizes the egg) because, in a natural conception, this is unobservable.¹ If you do not know the first day of your last menstrual period then an ultrasound scan can be used to accurately date your pregnancy.

This calculation will also give you your ‘due date’. Whilst it can be useful and exciting to have a predicted date of birth, remember not to rely too heavily on it. Only 4% of women actually give birth on their due date, while 70% of women deliver within 10 days of their due date.¹

Pregnancy is divided into three trimesters lasting roughly three months each:

• First trimester: weeks 1 to 12 
• Second trimester: weeks 13 to 27 
• Third trimester: weeks 28 to 40+ 

First trimester (weeks 1 to 12)

Weeks 1 to 3

The first trimester consists of the first 12 weeks of pregnancy. As the number of weeks you’re pregnant is dated from the first day of your last period you’re not in fact pregnant for the first 2 weeks, but your body is getting ready to ovulate. 

The path to pregnancy goes as follows:

• Day 1: first day of your period
• Day 14: you ovulate (an egg is released from one of your ovaries). This is usually 14 days after the first day of your period but maybe a couple of days shorter or longer depending on the length of your menstrual cycle
• Within 24 hours of ovulation, the egg is fertilised by a sperm and begins travelling from your fallopian tube to your uterus whilst it starts dividing into more cells²
• 5 - 6 days later the fertilised egg (now referred to as a blastocyte) implants into the wall of the uterus. You’re now pregnant

As soon as the blastocyte successfully implants, your body begins to produce the hormone human chorionic gonadotrophin (hcG) to sustain the pregnancy.² This is the hormone that pregnancy tests detect once it reaches a certain level in your urine.

Week 4 

This is the week before your period is due, towards the end of this week you may get a positive pregnancy test.

Symptoms

Typically the earliest sign of a pregnancy is a missed period, however, some women may also experience the symptoms of early pregnancy even before they have missed a period.³

Implantation bleeding happens to some women when the zygote implants into the uterus lining. This is often in the form of a small amount of dark red or brown blood.⁴

Fatigue is a common first symptom of pregnancy. Within the first few weeks of pregnancy, your body is working incredibly hard. It is producing high levels of progesterone which can cause you to feel extremely tired. This symptom should ease over the first trimester however, it can return later in your pregnancy. 

Sore or swollen breasts are another common early pregnancy symptom due to increased levels of hormones.³ You may also notice that your areola (the area around your nipples) becomes larger and darker. 

Increased urination can appear at various points during pregnancy for different reasons. In the early stages, your body increases the amount of blood you have, your blood is filtered through your kidneys which remove toxins and expel them in the form of urine.¹ The more blood you have, the more urine you produce.⁵

Week 5

Most women begin to suspect they're pregnant this week when their period does not arrive. Whether or not you have other symptoms you should take a pregnancy test. Tests are widely available and highly sensitive. Early detection tests will detect such low levels of hCG that you can have a positive test up to 6 days before your period is due.

Symptoms

Along with the symptoms highlighted in week 4 you may also experience:

Missed period, this is the most common first symptom of pregnancy.³ However, a missed period is not always a sign of pregnancy as there are other causes of amenorrhea (no period) such as:

• stress
• hormone imbalances
• excessive exercise
• dieting

Cramping is often mild and period-like and comes and goes over a few days. If these cramps are one-sided or severe contact your healthcare provider immediately. 

Headaches and dizziness can happen in early pregnancy due to hormonal changes and increased blood volume. 

Mood swings are normal due to increasing hormones. Unfortunately, this often continues throughout pregnancy.

Unexpected pregnancy

If you were not expecting to become pregnant and you don’t think that you wish to continue with the pregnancy then it is important to contact either your healthcare provider or self-refer to an abortion service in your area. The earlier you contact a healthcare provider, the earlier you can receive care and the more options that will be available to you.

What first steps do I take once I get a positive pregnancy test?

Once you have a positive pregnancy test the first thing to do is to contact your healthcare provider (usually your GP) so that you can be started down the antenatal (pregnancy) care pathway. 

You should also:

• Start taking a pregnancy supplement if you’re not already. These should contain both folic acid and vitamin D in recommended levels for pregnancy
• Make some lifestyle changes such as avoiding drinking and smoking. You can always talk to your healthcare provider about getting support to stop
• Discuss with your healthcare provider any medications you’re taking or any health conditions, such as diabetes, asthma, or epilepsy that you may have. Do not stop taking your regular medication without discussing it with your healthcare provider first
• Read about which foods and over-the-counter medications are not advised during pregnancy
• Cut down your caffeine intake to 200mg (two cups of coffee) a day⁶

Weeks 6 and 7

The embryo continues to grow, measuring 10mm, major organs start forming as do the buds which will eventually become limbs. A heartbeat can often be seen on vaginal ultrasound around now.

Symptoms

Morning sickness, thought to be caused by hormonal changes, usually starts around week 6 and can affect you any time of day or night. Nausea affects approximately 7 in 10 women during early pregnancy, with about 2/3rds of them also suffering from vomiting.¹ It should start to ease by week 14, although unfortunately for some women it can continue throughout the pregnancy or return in the third trimester.¹ There are different techniques you can try to help ease it.

Bloating due to increased levels of progesterone can lead to the appearance of a swollen abdomen and increased flatulence.

Constipation may occur as progesterone causes your digestive system to slow in early pregnancy.¹ Drinking plenty of fluids and eating plenty of fiber should help decrease it.

Strange tastes such as a metallic taste in your mouth can occur when eating food or randomly throughout the day. 

Bleeding gums can occur, so practising good mouth hygiene is important throughout your pregnancy. 

Weeks 8 to 10

Your baby is now called a foetus. The major organs and limbs continue to develop and they start to take on the appearance of a baby. You will likely have your first antenatal check-up around now.

Symptoms

You will have missed your second period by now, and are likely experiencing a number of different symptoms. Here are some others that may appear around this time if they haven’t already.

Increased vaginal discharge is normal during pregnancy. However, if the colour or smell changes could be a sign of an infection so speak to your doctor or midwife.

Food cravings, aversions, and heightened smell. You may find you’re craving food you’ve never liked or suddenly avoiding a long-term favourite. You can also have a heightened sense of smell which can make cooking different food uncomfortable. 

Skin and hair changes. Some women may experience the infamous ‘pregnancy glow’ with clear skin and thicker shinier hair. Unfortunately, it is also possible to experience more skin break-outs.

Week 11 and 12

In the final couple of weeks of the first trimester some women find that they’re starting to feel less exhausted and sick. By 12 weeks the foetus and placenta are fully formed, meaning that the baby will start growing and maturing in the next trimesters. 

This week you will likely attend your first scan as well as undergo various antenatal screening tests.

Symptoms

Indigestion (heartburn) is caused by hormones or the growing baby inside your abdomen.¹ There are lifestyle changes that could be useful as well as medications that are safe to take in pregnancy.

Feeling hot and increased sweating in pregnancy can occur due to hormonal changes and an increase in blood supply to the skin.

Varicose veins (swollen veins) can occur during pregnancy most commonly in your legs. They can be uncomfortable but aren’t dangerous. 

Urinary incontinence can occur both during and after pregnancy. It may be temporary during pregnancy but if it continues then you may require further treatment such as physiotherapy. There are exercises you can do daily to help reduce the risk of incontinence. 

Symptoms to contact your doctor or midwife about

• Severe vomiting can be an indicator you’re suffering from hyperemesis gravidarum. This can be serious as it can cause dehydration and a reduction in nutrients in your diet.¹ If you cannot keep food down or are frequently sick you should contact your doctor or midwife. If you are dehydrated you may require hospital admission, there are also anti-sickness medications your doctor can prescribe to help
• Headaches can be a normal occurrence during the first trimester however they can also be a symptom of more serious complications. Contact your doctor immediately if your headache is
  • severe 
  • accompanied by visual changes
  • accompanied by vomiting
  • accompanied by an increase in swelling or new facial swelling
• Bleeding during the first trimester can be common and doesn't necessarily mean there is something wrong.⁷ However, if you have vaginal bleeding you should always call your doctor or midwife immediately to be checked
• Stomach pain and cramping frequently occur in early pregnancy due to stretching ligaments, trapped wind, or constipation. It can however be a sign of something more worrying such as a miscarriage or an ectopic pregnancy. Contact your doctor or midwife immediately if you have:
  • severe stomach pain
  • cramping pain especially if it doesn't go away after resting
  • pain accompanied by vaginal bleeding, lower back pain, dark brown urine, or a change in vaginal discharge

Symptoms of a miscarriage

A miscarriage is a loss of pregnancy during the first 20 weeks. It is estimated that 1 in 5 pregnancies ends in a miscarriage, with the vast majority of these happening in the first trimester (before week 13).⁸

If you think you're suffering from a miscarriage then seek medical advice immediately either through your midwife, doctor, or the early pregnancy unit at your hospital.

Signs of an early miscarriage:

• Vaginal bleeding
• Stomach cramps and pain
• A discharge of fluid or tissue from your vagina
• No longer experiencing pregnancy symptoms

Symptoms of an ectopic pregnancy

Symptoms of an ectopic pregnancy usually begin between weeks 6 and 10.⁹ It is a rare but potentially life-threatening complication and occurs when a fertilised egg implants itself outside of the womb, most commonly in a fallopian tube.⁹ It affects roughly 1 to 2% of pregnancies.⁹

An ectopic pregnancy cannot be saved and treatment is often needed to safely end the pregnancy. Some ectopic pregnancies are symptomless and only picked up on routine pregnancy scanning however others may experience one or more of the following:⁹

• Abdominal pain which may be low down and one side 
• Vaginal bleeding or a brown watery discharge
• Pain in the tip of your shoulder
• Discomfort passing urine or stool, you may also experience diarrhoea

If you think you may have an ectopic pregnancy then contact your healthcare provider immediately.

Occasionally an ectopic pregnancy can cause your fallopian tube to rupture (split open). If you have any of the symptoms of an ectopic rupture then you must call for an ambulance or go to your nearest A&E. Symptoms of a rupture are:⁹

• Sharp, sudden, and intense stomach pain
• Feeling dizzy or faint
• Feeling nauseous or vomiting
• Looking very pale

Second trimester (weeks 13 to 27)

The fatigue and sickness of the first trimester should be starting to fade, although for an unlucky few this may continue on a while longer. This trimester is when many women feel their best, share their news with loved ones, and (if they wish) find out the sex of their baby.

Weeks 13 to 16

You have hopefully had your first scan by now and seen your baby bouncing around inside, although it will likely be a few more weeks until you feel those kicks. You should also have received your antenatal screening test results and be reassured that the rates of miscarriage drastically reduce after the first 12 weeks.

Symptoms

All of the symptoms from the first trimester can continue or start during the second trimester as well as new ones.

More energy could be on its way as you leave the first-trimester exhaustion behind. Exercising during pregnancy, at a level comfortable to you, is healthy and safe.

Baby bump. Many women find the development of a baby bump an exciting milestone in pregnancy. Remember though that every woman's bump will be different and there is no ‘right’ size. If your antenatal checks are ok then don’t worry about whether you’re ‘too big’ or ‘too small’.

Weight gain is normal in pregnancy. Expect to gain between 11.5kg - 16kg for a singleton pregnancy.¹⁰ Gaining too much or too little weight can cause health problems for you and your baby so it’s important to maintain a healthy balanced diet.

Change in sex drive is normal throughout pregnancy. Some women find in the second trimester they have an increase in sex drive due to hormones. Read more about sex in pregnancy if you have any concerns.

Weeks 17 to 19

Your baby is getting bigger, your bump is getting bigger and if you weren't already you should be feeling a bit better.

Symptoms

Feeling the baby move usually starts at 18 weeks, but don’t panic if it’s a little later for you. Movements initially feel like a ‘fluttering’ in the lower stomach and will be on and off to begin with depending on the baby’s position.

Back and pelvic pain can start to appear around now as your baby and bump grow, changing your centre of gravity and putting strain on your muscles and joints.¹ Pelvic pain, sometimes referred to as PGP or SPD can affect 1 in 3 pregnant women to some extent.¹¹ It is not harmful to your baby but can cause significant mobility issues.¹¹

Thrush is a yeast infection causing thick white discharge, itching, soreness, and redness around the vagina. Hormone changes during pregnancy can make you particularly susceptible. 

Skin pigmentation is common and occurs due to elevated melanocyte-stimulating and steroid hormone levels.¹ You may find you develop a dark line down your tummy or in patches. These should disappear within a year after your pregnancy.

Weeks 20 to 23

Week 20 marks the halfway point in your pregnancy. You should undergo an ‘anomaly’ scan around now where your baby's organs and development will be looked at using ultrasound. Your health should also continue to be monitored via regular blood pressure monitoring and urine and blood tests.

Symptoms

Leg cramps can occur, usually worse at night. Gentle exercise and simple leg stretches to improve leg circulation can help to relieve and prevent them.

UTIs can occur more frequently in pregnant women, if you have pain peeing, blood in your urine or need to go more frequently then contact your doctor or midwife.

Weeks 24 to 27

As your baby continues to get bigger and heavier you should start feeling stronger movements. Your belly will also be getting noticeably larger every week and you may find it starting to limit your movements.

Symptoms

Nose bleeds can be more frequent during pregnancy due to hormonal changes. Here are some tips for what to do if one occurs. If it doesn't stop then seek medical attention immediately. 

Piles (haemorrhoid) can occur during pregnancy and are more likely if you are constipated, they can be itchy, painful, or bleed when you pass stool. There are ointments that you can try to relieve some of the symptoms.

Stretch marks are unfortunately a common side effect of pregnancy, they should fade after you have given birth. Keep your skin well hydrated to prevent it from becoming dry and itchy.

When to contact your doctor or midwife immediately

• Swelling of your hands, feet, and legs can be normal in pregnancy and usually worsens towards the end of the day. However, a sudden increase in swelling, swelling of your face, or swelling associated with visual changes or headaches can be signs of a serious condition called pre-eclampsia and you need to seek medical advice immediately
• Breathlessness is common in pregnancy and can be physiologically normal.¹ However, it can also be a symptom of anaemia so should always be discussed with your doctor or midwife. If you have breathlessness and chest pain, dizziness, fainting, or heart palpitations then seek medical advice urgently
• Stomach pains or tightening are common in pregnancy and usually not dangerous. However, if they don’t ease on resting or are associated with any of the following syptoms then you must seek medical advice urgently:
  • Vaginal bleeding
  • Severe headaches
  • Sudden increase in swelling
  • Regular tightenings or cramping
  • Constant and severe pain
• Itchy skin although common in pregnancy can also be a sign that you're suffering from a rare liver condition called obstetric cholestasis (OC) which affects around 1 in 140 pregnant women.¹² The symptoms of OC are:
  • Itchy skin particularly on the hands and feet and worse at night
  • Dark urine
  • Pale poo
  • Yellowing of the skin or whites of the eyes
• Mental health concerns such as anxiety or depression can appear or worsen during pregnancy. If you have any concerns about your mental health then please discuss these with your midwife or doctor who will be able to support you

Third trimester (weeks 28 to 40+)

The final 12 weeks of pregnancy can be a time of anticipation and anxiety. It is normal to worry about impending labour, your baby’s health and how you will cope as a new parent. Your growing belly may also be starting to slow you down and as you prepare your lives to welcome your newest addition it can feel incredibly overwhelming.

Weeks 28 to 36

As your baby gains weight, its lungs are nearly fully developed and almost ready to make their entrance. You are likely experiencing many of the symptoms already discussed such as indigestion, weight gain, leg cramps and back pain. Here are some more symptoms that may appear if they haven’t already.

Symptoms

Braxton Hicks are tightenings of your belly. They may be uncomfortable but shouldn’t be painful and should resolve on rest. They’re often called ‘practice contractions’.

Leaking nipples can occur as your body gets ready to breastfeed. Talk to your midwife about possibly collecting some of the leaking colostrum to give to your baby after birth

Difficulty sleeping can be incredibly frustrating in the third trimester and happens due to a variety of reasons. Remember to sleep on your side and try using a pregnancy pillow to support you. 

Painful wrists and fingers can occur during pregnancy when there is increased pressure on the median nerve in your wrist.¹ This is called carpal tunnel syndrome. You should discuss these symptoms with your midwife.

Swollen legs are a common symptom in the third trimester, However if this swelling is in only one leg, is painful or the overlying skin is red then you need to let your healthcare provider know immediately as it could be a deep vein throbosis.¹

Symptoms of premature labour

A baby born before 37 weeks is classed as ‘premature’. Babies born prematurely usually require some support after birth however how much support, where, and what type of support they need will depend on how many weeks early they are born.

If you have any of these symptoms and you’re less than 37 weeks then you must call your midwife or maternity unit immediately.

• Regular contractions or tightenings
• Period-like pains
• A gush or trickle of fluid from your vagina
• Unusual for you back pain

Weeks 37 to 40+

From 37 weeks you’re now considered a ‘full term’ pregnancy. Your baby could arrive any time between now and 42 weeks gestation. The key symptoms to be aware of now are those which indicate labour may be starting.

Symptoms of labour

Contractions or tightenings often start as mild and infrequent. When they start to build in strength and frequency there is a good chance that labour is starting. 

Mucus plug or a ‘bloody show’ occurs when the mucus plugging your cervix comes loose. It can mean that labour will be starting in the next few hours to days.

Diarrohea is often reported by women in early labour as the baby’s head presses down on your intestines.

Waters breaking is the most obvious sign labour is starting. It can be either a trickle of fluid or an obvious gush. If you think your waters have broken always contact your midwife.

Back pain can be an initial symptom of labour, especially when the baby is in a ‘back to back’ position.

When to contact your doctor or midwife immediately

• Vaginal bleeding in any trimester should always be discussed immediately with your doctor, midwife or maternity unit
• Any symptoms of premature labour
• Waters breaking even if it is only a trickle you need to be assessed by a doctor or midwife
• Symptoms of pre-eclampsia such as severe headache, visual changes and a sudden increase in swelling
• Reduced movements of the baby. After 24 weeks if you feel that your baby is moving less than normal then contact your midwife or maternity unit immediately to be assessed
• Increase in thirst or urination can be a sign that you’re suffering from gestational diabetes. Make sure you report these symtoms to your midwife or doctor so you can be checked

Key points

• Pregnancy is a time of huge change and whilst often exciting it can also be filled with uncertainty and anxiety
• There is a wide variety of symptoms that you can experience during pregnancy, Even if you have been pregnant before it is unlikely that you will have the exact same experience
• If you have any worrying symptoms then always contact your healthcare provider immediately
• Remember that there is no question too small or silly to ask your healthcare provider. They will much prefer you come to them with concerns than to struggle through alone