Implantation Calculator

Find out when implantation likely occurs — and the earliest date for a pregnancy test.

What Is Implantation?

Implantation occurs when the fertilized egg (blastocyst) attaches to the uterine lining, typically 6-12 days after ovulation. This is when HCG production begins — the hormone detected by pregnancy tests.

When Should I Test?

For the most accurate result, wait until the day of your missed period. Testing too early can give a false negative because HCG levels may not yet be detectable.

Signs of Implantation

  • Implantation bleeding — light pink or brown spotting (much lighter than a period)
  • Mild cramping — lighter than menstrual cramps
  • Basal body temperature dip — a one-day temperature drop followed by a rise
  • Breast tenderness — similar to early pregnancy symptoms