Week 4 · First trimester
4 weeks pregnant
Baby's-breath floret
No size is stated this week — pregnancy is dated from before conception, and there is nothing yet to measure.
A Single baby's-breath floret (~2–4 mm) holds the scale of this week: tiny, bright, and complete enough to catch the eye when you look closely.
This week, inside
The embryo is about 2 mm long and growing quickly. It sits within an amniotic sac beside a yolk sac, while an outer layer of cells begins the work that will later become the placenta.
What you might be noticing
You may notice no symptoms at all, or a missed period may be the first clue. Tiredness, breast tenderness, and nausea can also begin during the first trimester.
- No symptoms
- Missed period
- Tired
- Tender breasts
- Nausea
Small things that help
Put a snack and water somewhere easy to reach. Start a simple question list for a future appointment, adding only what matters to you.
For the record
What was the first small detail that made this week feel different?
Zohra asks one of these every week, and keeps your answer. A year from now it is the part people say they are most glad they wrote down.
Where this came from
Not sure you are at week 4? Work out your due date — or see every week’s size on one chart, and the rest of the first trimester.
Keep this week
Zohra draws this same flower in the app, at this same size, and keeps what you write beside it — with your bump photos, the letters, and the sounds from your appointments.
Zohra arrives on the App Store for iPhone shortly. Everything on this site is free to read now, with no account and no sign-up.