Open Splash

When might implantation happen?

Implantation is when a fertilised egg settles into the lining of the womb. Tell us when you ovulated, or your last period, and we'll show the likely window.

In short: Implantation usually happens 6 to 12 days after ovulation, most often 8 to 10 days (Wilcox et al., 1999). This calculator estimates your implantation window and the earliest sensible pregnancy test date from your last period or ovulation date. Spotting alone cannot confirm pregnancy; a test can.

Runs on your device. Nothing is sent.
I know my

From a positive LH test (ovulation is usually the day after) or a temperature rise.

Your implantation window shows up here.

Implantation can't be felt reliably, and light spotting has many causes. If you have one-sided pain or heavy bleeding, get medical help.

How does the implantation calculator work?

  1. If you know your ovulation day (from LH tests or temperature), we use it. Otherwise we estimate it as 14 days before your next period.
  2. In a landmark study, implantation happened 6 to 12 days after ovulation, and 8 to 10 days in most pregnancies (Wilcox, 1999).
  3. hCG starts rising after implantation and takes a few days to reach a level home tests can detect.
  4. So the clearest test day is the day your period is due, about 14 days after ovulation.

Getting through the two-week wait

The days between ovulation and a reliable test can feel endless, and early symptoms look exactly like the days before a period. Testing too early often gives a negative result that changes later, which can be hard. If it helps, plan something for test day, and be gentle with yourself either way. Our guide to looking after your mind while trying has ideas.

When to see a doctor

  • You have a positive test and one-sided pain, shoulder-tip pain, bleeding or feel faint: get urgent help (possible ectopic pregnancy).
  • You've been trying for a year (or 6 months if you're 36 or over).
  • Your periods are irregular and you can't tell when you ovulate.

In the UK you can call NHS 111 for advice, any time. In an emergency call 999 (UK) or 911 (US).

Questions people ask

How many days after ovulation does implantation happen?

Usually 6 to 12 days after ovulation, most often 8 to 10 days (Wilcox, 1999).

What is implantation bleeding?

Some people notice light spotting around the time of implantation. It's usually lighter and shorter than a period. Many people don't have any, and spotting has lots of other causes, so it isn't a reliable sign.

Can I feel implantation?

There's no reliable way to feel it. Cramps and sore breasts around this time are also common before a period.

When can I take a test after implantation?

hCG needs a few days to build up. For the clearest result, test from the day your period is due.

Is anything I enter saved or sent?

No. Everything runs in your browser. Nothing is stored or sent, and the page makes no network requests when you use it.

Sources

  1. Wilcox AJ et al. Time of implantation of the conceptus and loss of pregnancy. NEJM, 1999
  2. NHS: Doing a pregnancy test
  3. NHS: Trying to get pregnant
  4. Wilcox AJ et al. Timing of sexual intercourse in relation to ovulation. NEJM, 1995

Written by the Splash team · Sources checked Oct 2026 · Updated

From ovulation to test day

This page works out one cycle. The Splash app keeps going: it learns from what you log and is saved on your phone by default.

  • Log LH tests and Splash pins your ovulation to the positive result.
  • Your test day follows automatically, and late days are counted kindly.
  • A trying-to-conceive mode that stays on your phone.
Get Splash, freeAll free tools

Log LH tests and Splash pins ovulation to your positive. Your test day follows automatically. Free, private, on your phone.

Splash log with ovulation and pregnancy test entries