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Pregnancy · Week 12 First trimester

12 Weeks Pregnant

At 12 weeks pregnant (first trimester), your baby is about the size of a lime. Here's what's developing and how you may feel.

Medically reviewed by Jordan Brooks, Certified pediatric sleep consultant· Last updated June 11, 2026

Baby this week

baby is the size of a Lime

size of a Lime

~2.1 in

2.1

Length

14 g

Weight

28

Weeks to go

📈 Grown +0.9″ since week 10

Wk 4Week 12Wk 40

Average measurements — every baby grows at their own pace.

Welcome to week 12. Your baby is growing fast and your body is changing. This week we cover development milestones, common symptoms, and what to prepare next as you move through your first trimester.

What's happening

Common symptoms this week

  • Fatigue
  • Back ache
  • Frequent urination
  • Morning sickness

Ask your provider

  • Which prenatal vitamin do you recommend for me?
  • Are any of my current medications a problem during pregnancy?
  • When is my first ultrasound scheduled — and what should I expect?

For your partner

Energy crash is real and not laziness. Take the dinner shift this week — a small thing that lands big.

This week — to do

  • Pick a provider you're comfortable with
  • Schedule your first ultrasound
  • Start the prenatal vitamin
  • Tell people on your timeline, not theirs
Frequently asked

Frequently asked — 12 Weeks Pregnant

How big is my baby at 12 weeks?

At 12 weeks, your baby is about the size of a lime — roughly ~2.1 in. Size and growth vary between babies; your provider tracks your baby’s growth at prenatal visits.

How many months is 12 weeks pregnant?

12 weeks is roughly 3 months pregnant. Pregnancy is most precisely tracked in weeks (40 weeks total from your last period), since "months" don’t divide evenly into weeks.

What symptoms are common at 12 weeks pregnant?

In the first trimester, fatigue, nausea (any time of day), tender breasts, frequent urination, and heightened smell are common as hormones surge. Symptoms vary widely — having few is also normal. Rest, eat small frequent meals, and keep up your prenatal vitamin.

When is my due date if I'm 12 weeks pregnant?

With 28 weeks to go, your estimated due date is about 28 weeks away. Due dates are estimates — only about 1 in 20 babies arrive exactly on the date, with most born within two weeks either side.

References

Sources we consult

We cross-check our editorial guidance against these authorities. Click any source for the original.

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