🔍 Pregnancy Tool

Pregnancy Conception Calculator

Reverse-calculate your pregnancy to find out when you most likely conceived. Useful for pregnancy tracking and dating.

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Estimate Conception Date

Calculate Based On:

First Day of Last Period

Average Cycle Length

Estimated Conception Date

Fertile Window

Due Date

About Conception Dating

Your doctor dates your pregnancy from the first day of your last menstrual period (LMP). Since conception typically happens about two weeks after your LMP, you are considered "two weeks pregnant" the day you actually conceive.

This calculator adjusts for your cycle length to give you the most accurate estimated date of conception and the fertile window leading up to it.