Enter your due date to estimate when conception likely happened, along with a likely window of about ten days and the estimated first day of your last period.
How to use it
- Pick your due date.
- Read the estimated conception date and window.
Questions about this tool
When does conception usually happen?
About two weeks after the first day of the last period in a typical 28-day cycle. The exact day is an estimate.
Is the date exact?
No. Sperm can survive for several days, so conception can fall anywhere in a short window.