Seven months pregnant covers weeks 25 through 28 of pregnancy. This span marks a major milestone: the beginning of your third trimester, which starts at week 28 and continues until delivery around week 40.
Why Months and Weeks Don’t Line Up Neatly
If you’ve tried to do the math yourself and gotten confused, you’re not alone. The problem is that pregnancy doesn’t divide cleanly into nine calendar months. A full-term pregnancy lasts 40 weeks, or 280 days, counted from the first day of your last menstrual period. That actually works out to closer to 10 lunar months (four weeks each) rather than nine calendar months (which average about 4.3 weeks each).
This mismatch is why different sources sometimes give slightly different week ranges for each month. But the most widely used breakdown places month seven at weeks 25 through 28. By the time you finish week 28, you’ve completed your seventh month and are solidly in your third trimester.
What’s Happening With Your Baby
The seventh month is a period of rapid brain growth, lung preparation, and weight gain. Your baby goes from roughly 340 millimeters (about 13.4 inches) at week 25 to around 370 millimeters (14.6 inches) by week 28, weighing close to 1 kilogram (2.2 pounds) by week 27.
At week 25, your baby’s eyelids open for the first time. They’re responsive to sound and touch, and a loud noise can trigger a startle reflex you may feel as a sudden kick. Their heart is beating at around 140 beats per minute, roughly twice the speed of yours.
Week 26 brings an important development in the lungs. The air sacs begin producing a substance that helps them expand and deflate properly during breathing. This is one of the key markers doctors look at when assessing whether a baby born early could breathe on their own. The brain, lungs, and digestive system are all in place by this point, though they’ll continue maturing for the rest of pregnancy.
By week 28, fat is building up beneath the skin, smoothing out the wrinkled appearance your baby had earlier. This fat layer will help regulate body temperature after birth.
Common Physical Changes at 7 Months
Entering the third trimester often means a noticeable shift in how your body feels day to day. Your uterus is now well above your belly button, putting pressure on your diaphragm and making deep breaths harder. Many people notice more shortness of breath, even during low-effort activities like climbing a short flight of stairs.
Backaches tend to intensify as your center of gravity shifts forward. Swelling in the feet and ankles is common, especially by the end of the day. You may also notice more frequent Braxton Hicks contractions, which are irregular tightening sensations across your belly. These are normal “practice” contractions and differ from real labor contractions in that they’re irregular, don’t get progressively stronger, and usually stop when you change position or rest.
Prenatal Tests Around This Time
One of the most common tests during the seventh month is glucose screening, typically done between weeks 24 and 28. You’ll drink a sugary liquid, then have your blood drawn an hour later to check your blood sugar level. A high reading doesn’t automatically mean gestational diabetes, but it does mean you’ll need a longer follow-up test to confirm. Gestational diabetes affects how your body processes sugar during pregnancy and can cause complications if it goes unmanaged, but it’s very treatable once identified.
If your blood type is Rh-negative (something identified through a blood test earlier in pregnancy), your provider will typically give you an injection around week 28 to prevent your immune system from reacting to your baby’s blood cells if the baby is Rh-positive.
Signs of Preterm Labor to Watch For
Because the seventh month falls right at the boundary of the third trimester, it’s worth knowing the signs of preterm labor. A baby born at 28 weeks can survive with intensive medical support, but every additional week in the womb significantly improves outcomes.
Contact your provider promptly if you experience any of the following:
- Regular contractions that come at consistent intervals, rather than the random tightening of Braxton Hicks
- A constant, dull low backache that doesn’t improve with rest or position changes
- Pelvic pressure that feels like the baby is pushing down
- Vaginal spotting or bleeding
- A gush or steady trickle of fluid from the vagina, which could signal your water breaking early
These symptoms don’t always mean labor is starting, but they need evaluation quickly. Early intervention can often delay delivery long enough to make a meaningful difference for the baby’s development.