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Pregnancy

Week-by-Week Pregnancy Tracker

Slide through your pregnancy to see how big your baby is, what's developing, and how you might feel — from week 4 to the finish line.

First trimester

Week 12

Week 422% thereWeek 40

Your baby is about the size of a

Lime

Length

2.1"

Weight

0.5 oz

Baby this week

Reflexes are developing, the digestive muscles are practicing contractions, and external genitals are forming. The fetus can open and close its fingers and curl its toes.

You this week

You're nearing the end of the first trimester, and nausea often starts to ease.

Tip: This is the window for first-trimester combined screening — confirm timing with your provider.

Full week 12 page →General info, not medical advice — see your provider.

Jump to any week

First trimester

Week 4 Week 5 Week 6 Week 7 Week 8 Week 9 Week 10 Week 11 Week 12 Week 13

Second trimester

Week 14 Week 15 Week 16 Week 17 Week 18 Week 19 Week 20 Week 21 Week 22 Week 23 Week 24 Week 25 Week 26 Week 27

Third trimester

Week 28 Week 29 Week 30 Week 31 Week 32 Week 33 Week 34 Week 35 Week 36 Week 37 Week 38 Week 39 Week 40

Sources & further reading

Development milestones are drawn from these authorities. This tracker is general information, not medical advice — every pregnancy is different, so bring questions to your OB or midwife.

Mayo Clinic — Fetal development week by week →American College of Obstetricians and Gynecologists (ACOG) →Cleveland Clinic — Fetal Development →NHS — Pregnancy week by week →AAP HealthyChildren.org — Prenatal & Pregnancy →

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