Why the date you start from changes the answer
Home tests detect hCG, and hCG only appears after implantation, which happens 6 to 12 days after ovulation. So every test date is really a count from ovulation. If you know your ovulation day, the maths is direct: earliest around 10 days later, most reliable at 14 days, near-certain at 15.
If you only know when you had sex, ovulation could have followed up to five days later because sperm survive that long. The calculator counts from that latest possible ovulation so you are not tempted to test too early. If you know your period was due on a certain day, that day is 14 days past ovulation in a typical cycle, which makes it the reliable day.
Reading an early negative
A negative before your period is due is not final. Late implantation and slower-rising hCG both delay a positive. Retest in two to three days rather than the next morning: hCG roughly doubles every 48 hours, so waiting gives a clearer answer. If you want to see where you are in the two-week wait day by day, the how many DPO am I page lays it out.
Frequently asked questions
How soon after unprotected sex can I take a pregnancy test?
Count from the latest day you could have ovulated, not from the day of sex. Sperm can survive up to five days, so ovulation may have happened up to five days later. Add ten days to that for the earliest a sensitive test could turn positive, and about fourteen days for a reliable result. In practice that is roughly two to three weeks after sex.
When should I take a pregnancy test after a missed period?
The day your period was due is already a reliable day for most tests. If it is negative and your period still has not come, retest two to three days later with first-morning urine. Ovulating later than usual is the most common reason for an early negative.
Can I test before my missed period?
Yes, with an early-detection test (around 10 mIU/mL sensitivity) from about 10 days past ovulation. Bear in mind that implantation can happen as late as 12 days past ovulation, so a negative before your period is due is not final. Testing early is fine as long as you plan to retest.
What time of day is best to take a pregnancy test?
First-morning urine is the most concentrated, so it gives the earliest possible positive. Once your period is a few days late, hCG is high enough that the time of day matters much less. Avoid drinking a lot of water right before testing early on.
Does the test brand matter?
Sensitivity matters more than brand. Early-detection tests detect around 10 mIU/mL of hCG, standard tests around 25, and some digital tests need 50 or more. The table on this page shows the first day each sensitivity could plausibly show a positive for your dates.
These calculators give estimates based on cycle averages and standard formulas. They are for general information only and are not medical advice. For anything concerning your health or pregnancy, talk to a qualified healthcare provider.