31 weeks pregnant in months
31 weeks pregnant is month 7 of pregnancy, in the third trimester. In calendar terms, 31 weeks is about 7.1 calendar months (7 months and 1 week). You’re 78% of the way to a 40-week due date, with 9 weeks to go.
A calendar calculation, not medical advice. Your provider’s dating ultrasound is the reference for your due date. Nothing you type leaves this page.
31 weeks at a glance
| Measure | At 31 weeks |
|---|---|
| Pregnancy month | Month 7 (weeks 28–31) |
| Trimester | Third |
| Calendar months | 7.1 (7 months and 1 week) |
| Counting 4-week months | 7.8 |
| Days pregnant | 217 |
| Weeks left until 40 | 9 |
Pregnancy months vs. calendar months at 31 weeks
Pregnancy months are counted in two ways. Most US pregnancy charts group the 40 weeks into nine “pregnancy months” of four or five weeks each, which puts week 31 in month 7. A calendar month is about 4.35 weeks (30.44 days), so 31 weeks of calendar time is 7.1 months. Both answers are correct for what they measure; your provider will track the pregnancy in weeks.
What’s usually on the calendar around week 31
- You’re in the third trimester, which starts at week 28. (source)
- From week 28 to week 36, visits are usually every two weeks. (source)
- The CDC recommends the Tdap (whooping cough) vaccine between 27 and 36 weeks of each pregnancy. (source)
Every pregnancy is different, and your provider’s schedule comes first.
Weeks around week 31
| Week | Pregnancy month | Calendar months | Trimester |
|---|---|---|---|
| 29 weeks | Month 7 | 6.7 | Third |
| 30 weeks | Month 7 | 6.9 | Third |
| 31 weeks | Month 7 | 7.1 | Third |
| 32 weeks | Month 8 | 7.4 | Third |
| 33 weeks | Month 8 | 7.6 | Third |
See every week from 1 to 42 on the pregnancy weeks to months chart.
Questions
Is 31 weeks pregnant 7 months?
Yes. Week 31 falls in month 7 on a standard pregnancy chart, and 31 weeks is also about 7.1 calendar months.
What is 31 weeks in months?
Divide the days by the average calendar month: 31 × 7 = 217 days, and 217 ÷ 30.44 = 7.1 months (7 months and 1 week). On a pregnancy chart, week 31 is month 7.
How many days is 31 weeks pregnant?
217 days, counted from the first day of your last menstrual period.
What trimester is 31 weeks?
The third trimester.
Track every week on paper
The printable pregnancy planner has this chart, trimester calendars, an appointment log and a 40-week countdown.
Sources
- ACOG, “How Your Fetus Grows During Pregnancy”
- Cleveland Clinic, “Your Prenatal Appointment Schedule”
- CDC, “Vaccinating Pregnant Patients” (Tdap)
This page explains calendar math. It isn’t medical advice; ask your provider about your own pregnancy.