Pregnancy week by week · trimester 1
🌱 4 weeks pregnant: your baby is about the size of a poppy seed
At 4 weeks pregnant, a tiny ball of cells is snuggling into the lining of your womb, and the very beginnings of the placenta are forming. You may only just have found out.
Your baby this week
Your baby is a tiny cluster of cells, about the size of a poppy seed, settling into the lining of your womb. This settling in is called implantation, and it is the very first home your baby will know. Some of those cells will become your baby, and others are already busy forming the placenta and the amniotic sac that will protect and nourish them. Pregnancy hormones are now being made, which is what a home pregnancy test picks up. It is a quiet, invisible week, but an enormous amount is beginning.
You this week
You might feel exactly the same as usual, and that is completely normal. Some mums notice a missed period, tender or tingly breasts, feeling more tired than normal, or needing the loo a little more often. A small amount of light spotting around the time your period was due can happen as the baby settles in. Feelings can be a jumble too: joy, shock, worry, or all three before breakfast. Be gentle with yourself while it sinks in.
Kind things to do this week
- Start a daily folic acid supplement (400 micrograms) if you have not already, and take vitamin D (10 micrograms) too.
- Cut out alcohol and smoking, and keep caffeine under 200mg a day (roughly two mugs of instant coffee).
- Write down the first day of your last period, as it helps work out your due date.
Appointments around now
No appointment yet. You can refer yourself to your local maternity service or speak to your GP once you know you are pregnant, so your booking appointment can be arranged for 8 to 10 weeks.
Questions to ask your midwife
- Do I need a higher dose of folic acid because of my health or family history?
- Are any of my current medicines safe to keep taking in pregnancy?
When to call your midwife or maternity unit
Please call your GP, midwife or NHS 111 if you have any bleeding, tummy pain that does not settle (especially low down on one side), or you are being sick so often you cannot keep fluids down. You are never wasting anyone's time.
OBubba from bump to baby
Follow your pregnancy week by week, free.
OBubba is free through pregnancy, with a weekly update, kick counting and contraction timing. On the day your baby arrives, the same app becomes your baby tracker.
Questions
Is it normal to feel nothing at 4 weeks pregnant?
Yes. Lots of mums feel no different at all this early. Symptoms usually build over the coming weeks, and having few or none says nothing about how your pregnancy is going.
When should I contact a midwife after a positive test?
As soon as you are ready. You can usually self-refer to your local maternity service or speak to your GP, so the booking appointment can happen by around 10 weeks.
Not sure how far along you are? Use the due date calculator.
Sources
OBubba gives general information. It is not medical advice and does not diagnose anything. Your midwife and maternity unit are always the right people to ask, any time of day or night.