Third Trimester Milestones Week by Week
Track third trimester milestones from week 28 through week 40 — glucose screening, GBS swab, full term, and your estimated due date, all calculated from your LMP.
The third trimester begins at week 28 and runs to your estimated due date at week 40. Key milestones include: the glucose challenge test (GCT) at 24–28 weeks, Group B Strep (GBS) swab at 35–37 weeks, "early full term" at week 37, "full term" at week 39, and your EDD at week 40. Babies born before 37 weeks are considered preterm; those born at 37–38 weeks are early term. The safest delivery window is 39–41 weeks. Enter your LMP in the calculator above to get exact dates for all of these milestones and plan your third-trimester appointments.
Use the full Third Trimester Milestones Week by Week
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