ParentSide
First trimester

4 Weeks Pregnant

Around a missed period

This week your baby is around the size of a poppy seed.

How your baby is developing

  • Around now many parents first wonder if they might be pregnant.
  • Early development is happening on a tiny scale, far too small to feel.

What may be happening in your body

  • A missed period is often the first physical clue this week, and it's what leads many people to test.
  • Breasts can feel tender, swollen, or tingly as the earliest changes begin.
  • Some notice mild tiredness now, while many feel no different at all yet.

How you may be feeling

  • Waiting to test — or seeing a positive result — can stir hope, disbelief, and nerves all at once.
  • Some people feel an urge to tell someone straight away, while others want to hold the news close for now.
  • A wave of early anxiety can surface before anything feels certain, and that's common this early.

Worth remembering

Symptoms — or none — vary widely this early and say little about how things are going.

A closer look

Why a missed period comes first

At four weeks, a missed period is often the earliest sign, because other symptoms may not have started yet. Some people already notice tender breasts or a little tiredness, while others feel completely normal — and neither says much about how things are going this early. This is often the week a home pregnancy test can confirm what's happening.

An uncertain start

The stretch before anything feels confirmed can be an anxious, in-between time, and pregnancy can be an emotionally stressful period for many people. Some notice worry or low mood surfacing even now. Talking it over with someone you trust can help you feel steadier.

Something you can do this week

If you think you may be pregnant, you might note questions for a midwife or doctor.

What comes next

Next week early symptoms like tiredness or nausea can begin for some.

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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