How early can home pregnancy tests show positive results?

When can I take a pregnancy test ?

After the egg is fertilized, it travels to the uterus (womb) and begins to implant in the uterine wall. If implantation is successful, tiny amounts of the pregnancy hormone, hCG, can start to appear in your urine from around 7 – 9 days after ovulation. It is this hormone that all home pregnancy tests detect. Some early pregnancy tests, such as the Clearblue® Early Digital Pregnancy Test and the Clearblue® Early Detection Pregnancy Test, can tell you whether you are pregnant as early as 6 days before your missed period (5 days before you expect your period)^2,3.

No matter when you test, you can be confident in the accuracy of a “Pregnant” result with any Clearblue® Pregnancy Test.⁴

But if you are testing early, before your period is due, you should be aware that even if your result is not pregnant, you may still be pregnant. This is because human Chorionic Gonadotropin (hCG) levels vary from woman to woman, and there may not yet be enough of the hormone for the test to give a positive result.

The day of your expected period is the day your period is due to start. If you still haven’t got your period the next day, this is the first day of your “missed period”. If you see instructions in the leaflet telling you, you can take a test 5 days before expected period, this is the same as 6 days before your missed period. The Clearblue® Early Detection Pregnancy Test, can detect hCG as early as 6 days before your missed period³.

40 Pieces Home Early One Step Pregnancy Test Cassette

You can use the calculator below to check when you can take a pregnancy test. Most women have menstrual cycles that vary in length from cycle to cycle, which is perfectly normal. If your cycles tend to vary, you should use the longest cycle you’ve had in the last 6 months, in the calculator below.

How do pregnancy tests work?

All home pregnancy tests detect the ‘pregnancy hormone’, human Chorionic Gonadotropin (hCG) in urine. In pregnancy, hCG is produced first by the fertilized egg and later the placenta. A fertilized egg typically implants into the lining of the uterus (womb) as early as 6 days after fertlization, when tiny amounts of hCG start to appear in the mother’s blood and urine. Though hCG levels are very low at first, the level rises rapidly and predictably in the first weeks of pregnancy.¹

How accurate are pregnancy tests?

When it comes to taking a pregnancy test, all Clearblue® tests are over 99% accurate at detecting pregnancy from the day you expect your period⁴. Some tests can also be used as early as 6 days before your expected period. Just find the right home pregnancy test for you and your needs, and make sure you follow the instructions carefully.

What is the best time of the day to take a pregnancy test?

If you take a pregnancy test after you have missed your period, then you can test at any time of day as your hCG levels will be high enough to be detected by most home pregnancy tests.

However, if you’re testing before you expect your period, when any hCG level would be much lower, you should test with the first urine of the day (when hCG levels are most concentrated) and avoid drinking a lot of liquid (including water) before testing.

Also, make sure to use an “early test” if you are testing before you miss your period.

All you need to know about testing early for pregnancy.

How pregnancy tests work

Even though hCG levels are very low at first, they increase rapidly in the first weeks of pregnancy.
If a pregnancy test detects hCG, your result will be positive and you can be confident that you are pregnant.
If the test is negative, but you tested before the day of your expected period, then there is the possibility you could still be pregnant but your hCG levels were too low for the test to detect. You should test again in a few days’ time, or when your period is due. If you get a negative result on or after the day you expect your period, but still think you might be pregnant, see your doctor.

Rise of pregnancy hormone (hCG) in early pregnancy

If you are testing early, before your period is due, you should be aware that even if your result is not pregnant, you may still be pregnant. This is because human Chorionic Gonadotropin (hCG) levels vary from woman to woman, and there may not yet be enough of the hormone for the test to give a positive result. HCG levels rise rapidly in early pregnancy, as shown in the graph below, meaning that if you test again on the day you expect your period, the levels should be high enough, to give a positive result (if you are pregnant).