Implantation Calculator

Estimate your implantation window — 6 to 12 days after ovulation. Enter your ovulation date or last period date to calculate.

Calculate Your Implantation Window

Implantation Window

Implantation timing varies. These are estimates only.

When does implantation occur?

Implantation is the process by which a fertilised egg (blastocyst) attaches to the lining of the uterus. It typically occurs 6 to 12 days after ovulation, with the highest incidence on days 8–10 post-ovulation (DPO), according to a landmark study published in the New England Journal of Medicine (Wilcox et al., 1999).

Before implantation, the fertilised egg travels down the fallopian tube and undergoes cell division over 5–7 days, reaching the blastocyst stage before burrowing into the endometrium.

What is implantation bleeding?

Some people experience light spotting when the blastocyst implants. This "implantation bleeding" is typically lighter than a period — pink or brown in colour — and lasts 1–3 days. However, studies suggest fewer than 25% of pregnant people experience it. Spotting during the implantation window does not confirm pregnancy.

When to take a pregnancy test

After implantation, the developing embryo begins producing hCG (human chorionic gonadotropin), the hormone detected by pregnancy tests. hCG levels double roughly every 48–72 hours in early pregnancy. Most sensitive home tests can detect pregnancy 10–14 days after ovulation — around the time of your expected period. Testing earlier may give a false negative.

Period Tracker Team

References: Wilcox AJ et al., "Time of Implantation of the Conceptus and Loss of Pregnancy," NEJM 1999. Last reviewed June 2026.

Implantation FAQ

When does implantation occur?

Implantation typically occurs 6–12 days after ovulation, with most implantations on days 8–10 DPO (days past ovulation).

What is implantation bleeding?

Light spotting (pink or brown) that may occur when the fertilised egg attaches to the uterine lining. It lasts 1–3 days and is lighter than a period. Not everyone experiences it.

When is the earliest I can take a pregnancy test?

Most home tests can detect hCG 10–14 days after ovulation — around the time of your missed period. Testing before this may give a false negative.