Pregnancy Week-by-Week Tracker
Enter the first day of your last period and we'll show you exactly where you are — plus what's next.
How this works
Enter the first day of your last menstrual period (LMP). The tracker computes days elapsed, converts to weeks + days (the standard OB dating format), and locates you in a trimester. Milestones are pulled from the standard ACOG-aligned Tennessee prenatal care schedule.
Limitations
LMP dating assumes a regular 28-day cycle. If yours isn't, or if your first ultrasound disagrees, use the ultrasound date. See the due-date calculator for cycle-length adjustment.
Sources: ACOG standard prenatal care schedule.
Frequently asked questions
Weeks are counted from the first day of your last menstrual period (LMP), not from conception. Conception happens roughly at the start of week 3. This is the standard OB dating convention in Tennessee and worldwide.
Trimester 1: weeks 1–12. Trimester 2: weeks 13–26. Trimester 3: weeks 27–40.
Pregnancy is 40 weeks, or a bit over 9 calendar months. OB timing is always in weeks and days because it's more precise.
The best window for 3D/4D or HD Live imaging is 26–32 weeks. See our full guide to timing an elective ultrasound in Tennessee.