When can I take a pregnancy test?
A pregnancy test is most reliable from the day your period was due. A sensitive early test can sometimes pick something up a few days before, but is often still negative then. If you do not know when your period is due, test at least 21 days after unprotected sex.
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Everything is calculated on your own device. We store nothing and send nothing anywhere.
This is an estimate, not medical advice and not contraception. If in doubt, ask your GP or midwife.
How we calculate
Your next period is your last period plus your cycle length. From that day a test is reliable. A sensitive early test can work at the earliest about 4 days before. From a date of unprotected sex, we count 21 days.
Negative but no period?
Test again a few days later, ideally with your first morning urine. If your period still does not come, talk to your GP.
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Frequently asked questions
How early can I take a pregnancy test?
A sensitive early test can work at the earliest about 4 days before your expected period. A test is reliable from the day your period was due.
How many days after sex can I test?
If you do not know when your period is due, test at least 21 days after unprotected sex.
My test is negative but my period has not come. What now?
Test again a few days later with morning urine. If it stays negative and your period does not come, talk to your GP.
Does the time of day matter?
Early testing works best with your first morning urine, when the pregnancy hormone is most concentrated.
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Sources: NHS, Periods and fertility in the menstrual cycle; NHS, Pregnancy due date; ACOG, Methods for estimating the due date.