Conception Calculator

Your details

The first day of bleeding of your most recent menstrual period.
Days from the start of one period to the start of the next. Shifts the assumed ovulation day.
days
Used to estimate gestational age now. Leave blank to use the current date.
Estimated conception date
15 Nov 2025
Day of the weekSaturday
Likely fertile window10 Nov 2025, 15 Nov 2025
Conception date range13 Nov 2025, 17 Nov 2025
How far along now40 weeks 0 days
Estimated due date8 Aug 2026
40 wk
First trimester<13Second trimester13-27Third trimester27+

You most likely conceived around 15 Nov 2025 (a Saturday).

  • Conception happens at ovulation, roughly 14 days after the start of your last period in a typical 28-day cycle.
  • The exact day is uncertain, so treat 13 Nov 2025, 17 Nov 2025 as the realistic window rather than a single date.
  • Sperm can survive up to five days, so intercourse anywhere in the fertile window can lead to conception on the ovulation day.
  • Based on the date you entered, you are about 40 weeks 0 days pregnant, with a due date around 8 Aug 2026.

Next stepAn early dating ultrasound gives the most accurate timing, share this estimate with your provider.

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