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Third trimester

31 Weeks Pregnant

Tired and excited

This week your baby is around the size of a coconut.

How your baby is developing

  • Your baby keeps putting on size toward birth.
  • Growth continues steadily this week.

What may be happening in your body

  • Braxton Hicks tightenings — your bump briefly going hard and firm — can start to feel more noticeable now.
  • Some babies are head down by now — you may even have felt your baby move into place and seen your bump shift downwards. Others don't engage until much later, including when labour starts.
  • An ache low in your back can build as pregnancy softens your ligaments and shifts how you stand.

How you may be feeling

  • Tiredness can weigh on your mood, so patience with yourself may be harder to find on some days.
  • Eagerness to meet your baby and nerves about the birth can rise at the same time.
  • Some people feel pulled to organise and prepare, while others just want to rest — both are common.

Worth remembering

Braxton Hicks are usually painless. Because you are under 37 weeks, if tightenings become painful or start coming regularly, call your midwife or maternity unit urgently — do not wait until the next day, even if it is the middle of the night.

A closer look

What practice tightenings are

Braxton Hicks are your bump tightening and then relaxing again — often called practice contractions. NHS describes them as usually painless, though they may feel uncomfortable; they generally do not last long, do not happen very frequently, and do not build up the way labour contractions do.

Why your lower back aches

During pregnancy the ligaments in your body naturally soften and stretch to prepare you for labour, which can strain the joints of your lower back and pelvis. Flat, supportive shoes, resting when you can, a warm bath, and good back support when you sit help many people. Because back pain in the second or third trimester can sometimes be a sign of early labour, contact your doctor or midwife if it is new or worsening.

Something you can do this week

Pacing yourself and accepting help can make a real difference.

What comes next

Your baby often settles toward a head-down position over the coming weeks.

Professional support

Services ParentSide defines for this stage. Each page explains what the service covers and which professionals are approved to provide it.

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Sources and updates

Last reviewed:
This content is based on estimated averages and general information; it does not replace medical advice. If you are concerned about yourself or your baby, speak with a qualified healthcare professional.

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