What pregnancy week 12 means
End of the first trimester approaching. “12 weeks pregnant” means 12 weeks have passed since the first day of the last menstrual period — the standard way pregnancy is dated. Conception usually happened about two weeks after that date, so the baby’s own age (fetal age) is roughly 10 weeks. Week 12 runs from 12 weeks 0 days to 12 weeks 6 days; on the following day the pregnancy is 13 weeks.
Your baby at 12 weeks
Reflexes are developing: the fingers can open and close and the baby may react to touch on the outside of the abdomen, though you will not feel it. The intestines move from the umbilical cord into the abdomen.
A common way to picture it: the baby is now about the size of a lime — roughly about 5.4 cm and about 14 g. These are averages; babies grow at different rates, and ultrasound measurements vary.
Your body at 12 weeks
The uterus begins to rise above the pubic bone, and a small bump may start to show, especially in a second pregnancy. Many people choose to share their news around this time.
Care and appointments around week 12
If you have not had a dating scan yet, it is often scheduled around now. It is also a common time to think about how your work and any leave arrangements will fit with your due date.
The timing of tests and appointments differs between countries and care providers. If anything worries you — such as bleeding, severe pain, fluid leaking, fever — contact your midwife, doctor or maternity unit straight away rather than waiting for your next appointment.
Week 12 in your pregnancy timeline
Week 12 is in the first trimester (weeks 1–13) and in pregnancy month 3, which covers roughly weeks 9–13. The second trimester begins in 2 weeks.
| Pregnancy start (first day of last period) | |
|---|---|
| Estimated conception | |
| Second trimester begins (14 weeks) | |
| Third trimester begins (28 weeks) | |
| Full term (39 weeks) | |
| Estimated due date (40 weeks) |
Dates assume you are exactly 12 weeks 0 days today. For dates based on your own last period, use the calculator above or the main Pregnancy Calculator.
12 weeks pregnant in days and months
12 weeks is 84 days of pregnancy — 30% of a 40-week pregnancy. Counted in calendar months, 12 weeks is about 2.8 months, which is usually described as month 3 of pregnancy. Months are only a rough grouping; healthcare professionals almost always talk in weeks and days because they are more precise. See Pregnancy Month Calculator for how weeks map to months.