Implantation Calculator
Find your likely implantation window, the few days when a fertilised egg settles into the womb lining. We also show when any implantation spotting could appear and the earliest day a test becomes reliable.
Your dates
From an OPK surge, a temperature rise or tracking.
We estimate ovulation as your cycle length minus 14 days.
Enter a date to see your likely implantation window.
Likely implantation window
Most likely around (about 8 to 10 days after ovulation).
Any spotting
Earliest test
Period due
Not everyone has implantation spotting, and its absence means nothing. A test is most reliable from your missed period (around ).
How implantation unfolds
Read more
Next step
Due Date Calculator
Got a positive test? Find your due date and how far along you are.