You just found out you're pregnant and your healthcare provider asked: "When do you think you conceived?" You're not entirely sure. You know your last menstrual period, but conception happens roughly two weeks after that. You need to work backwards from your due date or forwards from your last period. You could calculate it manually by counting backwards 266 days from your due date. But that requires knowing pregnancy formulas and careful calendar counting. Or you could use a conception calculator to instantly show your estimated conception date was December 22nd based on your due date of September 15th. A conception calculator estimates when your baby was conceived by working backwards from your due date or calculating from your last menstrual period, accounting for typical ovulation timing. Conception calculators are used by pregnant women understanding their pregnancy timeline, healthcare providers confirming pregnancy dating, couples planning pregnancies, and anyo...