Week 6 of 40 · first trimester

Week 6 of pregnancy

Week 6 is early days: much of what happens now is too small to see, and you may be the only one who knows.

Sources checked October 30, 2026

A woman on her sofa writing in a small notebook
Week 6
34 weeks to go
About the size of
a lentil
The Log menu during pregnancy: Symptom, Appointment, Sleep, Mood and Contractions
The Log menu during pregnancy.
Illustration of a lentil, the average size of a baby at 6 weeks
Your baby this week

About the size of a lentil

SizeAbout a lentil
Length0.24 in (0.6 cm), measured from head to bottom (crown to rump) [1]
TrimesterFirst trimester
Weeks to goAbout 34 to your due date

These are averages. Every baby grows at their own pace.

What is forming this week

Arm and leg buds are forming, with tiny dents where the ears will be and a bump where the heart is. [1]

How you may feel

Morning sickness can come at any time of day, though it's often worse when you first wake up. [1]

Everyone's pregnancy is different. If something worries you, call your midwife or doctor.

One thing to do this week

Try 6 small meals a day and keep a snack by your bed. If you can't keep food down, talk to your midwife or doctor. [1]

Questions you could bring to your next appointment

  • When is my dating scan, and what will it check?
  • Which medicines and supplements are fine to keep taking?
  • Who do I call if I'm worried between appointments?

Questions

When is the first scan?

In England the NHS offers the first scan, often called the 12-week or dating scan, at 11 to 14 weeks. In the US the timing of the first ultrasound depends on your care team, so ask at your first appointment.

Why is pregnancy counted from my last period?

Weeks are counted from the first day of your last period. Pregnancy is assumed to start about 2 weeks after that, so week 4 is only around 2 weeks after conception.

Is my baby exactly this size?

Probably not exactly. The length is the average the NHS gives for this week. Your scan results are the ones that count, and your midwife or doctor is the person to ask about them.

Sources

  1. NHS: 6 weeks pregnant guide Checked October 30, 2026
  2. ACOG: How your fetus grows during pregnancy Checked October 30, 2026
  3. NHS: Ultrasound scans in pregnancy Checked October 30, 2026

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