First trimester. Weeks 1-11
What happens to your body:
You’ll experience at least some of these symptoms:
- Missed period

- Sore, tender or tingling breasts
- Increased vaginal discharge
- Mood changes
- Need to go to pass urine more often
- Tiredness
- Period-like pains in your tummy
- Morning sickness
- Your nipples and the surrounding area (areola) darken and become itchy
- Breasts feel fuller and more sensitive
- Sense of smell sharpens
What happens to your baby:
- Weeks 1-4. The cells of your fertilised egg are multiplying quickly
- Weeks 5-8. Your baby develops to the size of a grape. Small buds appear which begin to develop into limbs. Their tiny heart is beating
- Weeks 9-12. Your baby is fully formed. They’re about 7 cm long and can yawn, swallow and suck their fingers
Second Trimester. 12-23 weeks
What happens to your body:
- After 12-14 weeks, you may find your morning sickness and tiredness begin to recede. You may feel more energetic and ‘well’
- From 18 weeks you may feel fluttering feelings in your tummy. By about week 20, you’ll start to feel very definite movements
- Your breasts may be getting bigger, so make sure you get fitted for a bigger bra to keep comfortable
What happens to your baby:
- 15-20 weeks. At 14 weeks, they’re about 8cm. Your baby is very rapidly getting bigger. By 16 weeks, they’re about 11.5 cm
- They have hair, eyebrows and lashes. They can make a fist and grip. They even have fingerprints
- Your midwife or GP will now be able to use an ultrasound device to detect their heartbeat
- 21-24 weeks. They’ve developed a daily routine of sleeping and waking and moves around quite a bit when awake
- 23 weeks. They’re 28 cm long and covered in fine hair
Third trimester. Week 24+
What happens to your body:
- 26 weeks. As your bump gets bigger and higher up, your tummy button may actually pop out (it’ll pop back into place after your baby’s birth)
- You may find it difficult to sleep at night because that’s when your baby is most active
- You may find your breasts are much bigger
What happens to your baby:
- 24-30 weeks. They respond to touch and sound, which can be a lot of fun. You’ll even feel it when they get hiccups
- 26 weeks. Their eyes open for the first time: they will have blue or dark blue eyes
- 30 weeks. They’re about 40 cm long
- 31 weeks. Your baby is still only half their birth weight, so they’ve got a lot of growing to do
- Your baby’s organs are fully formed and their immune system’s starting to develop
- Their skin is much less wrinkled, thanks to the fat their body is storing in preparation for those first days in the outside world
35 - 40 weeks
What happens to your body:
- You might start noticing ‘Braxton Hicks’ contractions. These are when your womb does practise contractions for birth
- Your energy levels decrease and you get breathless easily
- It’s a good idea to listen to your body and get as much rest as possible
What happens to your baby:
- Your baby is becoming noticeably heavier by the day
- From 36 weeks their head may be ‘engaged’. For first-time mums this is when the head moves down into your pelvis. However, some babies and subsequent babies don’t do this until labour starts
- Your baby now has very little room to move, although as you’ll be aware, they can still kick and punch
- Your baby is gaining about 230 g a week and is about 48-55 cm long