Implantation calculator
Implantation calculator
Enter your last period or your ovulation date to estimate when implantation could happen and when to test.
Updated
In short
When does implantation happen?
Implantation, when a fertilised egg attaches to the lining of the uterus, happens 6 to 12 days after ovulation, most often on days 8 to 10. That comes from a study that tracked hCG, the pregnancy hormone, in daily urine samples. hCG starts to rise after implantation, so a test is most reliable from the day your period is due.
Your estimate
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This is an estimate, not a diagnosis or birth control.
General information, not medical advice. Your doctor or midwife can tell you what your own results mean.
How it's calculated
- Ovulation ≈ first day of last period + cycle length − 14 days, or the ovulation date you enter.
- Implantation window = ovulation + 6 days to ovulation + 12 days.
- Most likely = ovulation + 8 to + 10 days, where most implantations fell in the study.
- Missed period ≈ ovulation + 14 days, the first day a home test is reliable.
Gyne learns your real cycle and adjusts these estimates as you log.
Frequently asked questions
What does implantation bleeding look like?
Some people notice light spotting, pink or brown, around the time of implantation. It's lighter and shorter than a period. Many people have none at all.
Can I feel implantation?
Some people notice mild cramps, but there's no reliable sign. The same feelings are common before a period, so a test is the only way to know.
How soon after implantation will a test be positive?
hCG appears in urine once the embryo implants and then rises quickly. Most home tests are reliable from the first day of a missed period.
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