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Estimate your delivery date, track weekly gestational age, map peak fertile ovulation windows, and plan key ultrasound milestones with private in-browser timelines.
Built for expecting parents, fertility tracking, and clinical milestone preparation.
Your personal menstrual cycle dates, fertility windows, and gestational timelines are calculated locally in your browser memory.
Adjusts standard 280-day gestational age calculations for shorter (21-day) or longer (40-day) menstrual cycles.
Export an itemized schedule of anatomy scans, viability milestones, and trimester transitions to share with healthcare providers.
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Clear answers regarding gestational age, Naegele's Rule, fertile windows, and milestone timing.
Naegele's Rule adds 280 days (40 weeks) to the first day of your last menstrual period (LMP), assuming a standard 28-day menstrual cycle. For non-28-day cycles, the calculation adjusts by adding or subtracting the cycle difference.
Ovulation occurs approximately 14 days before your next expected period. If your cycle is 32 days, ovulation occurs around Day 18 (4 days later than average), shifting your estimated due date 4 days later.
Sperm can survive in the reproductive tract for up to 5 days, while an unfertilized ovum remains viable for about 12 to 24 hours after release. This creates a 6-day fertile window comprising the 5 days leading up to ovulation plus the day of ovulation.
First Trimester: Weeks 1 through 13. Second Trimester: Weeks 14 through 27. Third Trimester: Weeks 28 through 40 (and beyond until delivery).
Early term begins at 37 weeks 0 days. Full term is defined as 39 weeks 0 days to 40 weeks 6 days. Late term is 41 weeks, and post-term is 42 weeks and beyond.
Yes. If you know the exact date of conception or ovulation (e.g. through IVF embryo transfer or ovulation testing), select 'Conception Date' to calculate a 266-day gestational timeline.
Yes. Use the 'Reverse Due Date Planner' tab to enter your target delivery date and discover the exact fertile window needed to conceive.
Yes. Click 'Download PDF Schedule' to generate a clean, vector-rendered milestone checklist including target dates for heartbeat detection, nuchal scans, anatomy scans, viability, and due date.
No. All date calculations run 100% locally in your device's browser memory. Your reproductive and maternity health data remains completely private.
No. Clinical ultrasound biometry (such as crown-rump length measured during the first trimester) remains the most accurate clinical standard for fetal gestational age assessment.