What is implantation?
Implantation is when a fertilized egg attaches to the uterine lining. In a prospective study, it occurred 6 to 12 days after ovulation, most often on days 8 to 10.
Most people don't feel implantation happening, but knowing your implantation window can help you plan when to take a pregnancy test for the most accurate results.
How to use the implantation calculator
Enter these two details:
- The first day of your last period
- Your average cycle length
The calculator estimates ovulation, then adds 6 to 12 days for a possible implantation window. Both dates depend on a calendar estimate and may differ from what happens in your body.
How do you know if implantation was successful?
After fertilization, the developing embryo travels to the uterus. Implantation timing cannot be confirmed from symptoms or calendar dates alone.
When can you take a pregnancy test after implantation?
Most home tests can be used from the first day of a missed period. An early negative may need repeating after a few days. If you do not know when your period is due, test at least 21 days after the last unprotected sex.
Why wait?
Home pregnancy tests detect human chorionic gonadotropin (hCG), a hormone your body starts producing after implantation. However, hCG levels need time to build up to detectable levels:
Use the pregnancy test calculator for date estimates and advice on repeating a negative test.
