All weeks

First Trimester

Week 3 of pregnancy

Your baby is the size of a poppy seed.

Baby at 3 weeks

  • The fertilised egg (blastocyst) reaches the uterus.
  • Implantation begins around day 6-10 after ovulation.
  • Cells are differentiating into placenta + embryo.

What you may feel

  • Possibly nothing yet — implantation may not have happened.
  • Light spotting in some women (implantation bleeding).
  • Mild cramping.

This week’s checklist

  • Continue folic acid.
  • Pregnancy test will likely still be negative — too early.
  • Avoid alcohol entirely from now.

Key milestone

Implantation — the blastocyst embeds in the uterine lining.

Doctor / midwife visits

No appointments yet.

Top foods this week

Educational only — not medical advice. Always consult your midwife or GP. Sources: NICE NG201 antenatal care, NICE NG207 inducing labour, NHS, RCOG. Read the full medical disclaimer.