Use your due date to calculate the date of conception.
If you are pregnant, you may be wondering what your actual date of conception was. While there is no way to say definitively what day you conceived your child, there are ways to calculate based on your expected due date, menstrual cycle and ovulation day. For a woman with a 28-day cycle, her date of conception is most likely around two weeks after the first day of her menstrual cycle; but since every woman is different, this is merely an estimation.
Instructions
1. Count back 266 days or 40 weeks from your expected due date.
2. Count 11 days after first date of your last menstrual period and circle 11th day. Do same for 21 days after ovulation. For a woman who ovulates regularly, your conception date is most likely between these two days.
3. Look at your ovulation calendar for your approximate conception date. If you keep track of your ovulation by charting your basal body temperature, ovulation predictor kits or other means, your conception date will be in the 24 hours following ovulation.
4. Count back 14 days from day you expected your next period. If you normally have a 30 day menstrual cycle, count 30 days from first day of your menstrual cycle and subtract 14 days from that date to find out your approximate day of ovulation. This is because the average woman has a luteal phase (time period between ovulation and your next menstrual cycle) of 14 days.
Tags: menstrual cycle, conception date, date conception, days from, after first, back days
