If you think you might be pregnant, you want to know right away. But it’s important to understand what’s happening in your body so you know how soon you can test. Read on to learn all about when to use a pregnancy test, the types of tests available and more!
Calculate when I can take a pregnancy test
*This tool is for guidance purposes. Always use the leaflet provided with your product to work out when you can test.
Calculate when I can test
In this article
- Calculate when I can test
- What is a pregnancy test
- How accurate are pregnancy tests?
- When can I take a pregnancy test?
- What is the best time of day to take a pregnancy test?
- All you need to know about testing early for pregnancy.
- Rise of pregnancy hormone (hCG) in early pregnancy
- What are the different types of pregnancy tests?
- What are the advantages of using a home pregnancy test?
- How to read a pregnancy test?
- What should I do if my pregnancy test is positive?
- Pregnancy tests at the doctor's office
- FAQs about pregnancy tests
What is a pregnancy test
If you think you might be pregnant, a pregnancy test can give you a result that confirms whether or not you are pregnant. More precisely, it can detect a specific hormone your body produces after you get pregnant, known as human chorionic gonadotropin (hCG), in your urine or blood. When an egg is fertilized by a sperm, which happens in the fallopian tube, or oviduct, the fertilized egg travels to the womb (or uterus) and implants in the uterine wall. It is only after this implantation occurs, around 7-9 days after conception, that hCG starts to appear in blood and urine. The most sensitive home tests can detect hCG as early as 6 days before your missed period.
So, if you’ve had sex and think there’s a chance you could be pregnant, whether or not you are trying to have a baby, a home pregnancy test will help you find out. All home pregnancy tests are over 99% accurate from the day you expect your period1.
How accurate are pregnancy tests?
When used correctly, pregnancy tests are incredibly accurate, with home pregnancy tests offering an accuracy rate of over 99% from the day you expect your period. However, some of the most sensitive tests on the market can detect pregnancy as early as 6 days before your missed period, as they can detect very low levels of hCG.
If you test before you expect your period, and your result is positive, you can be sure you are pregnant. However, if you get a negative result, it is still possible you may be pregnant but the level of hCG is not yet high enough to be detected. You should wait a few days before testing again in this case, if you still think you could be pregnant.
Another couple of things to consider when you test early is that you should always test with your first urine of the day, as that’s when any hormone present will be at its most concentrated, and also you shouldn’t drink too much liquid, including water before you test as it can dilute your urine and therefore any hCG hormone it contains.
When can I take a pregnancy test?
If you think you might be pregnant, you want to know now, but understanding a little bit about the biology of it can help you know how soon you can 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 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 (which is 5 days before your expected period)2.
No matter when you test, you can be confident in the accuracy of a 'Pregnant' result with any Clearblue Pregnancy Test.
But if you are testing early, you should be aware that even if your result is not pregnant, you may still be pregnant. This is because levels of human Chorionic Gonadotropin (hCG) 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 five days before expected period, this is the same as six days before your missed period. The Clearblue® Early Detection Pregnancy Test, can detect hCG as early as 6 days before your missed period2.
You can use the calculator above 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 above.
What is the best time of 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 if you are pregnant, 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 your hCG level would be much lower if you were pregnant, 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).
Rise of pregnancy hormone
(hCG) in early pregnancy
concentration
period
period
So, if you are thinking of testing before your missed period, why not try Clearblue Early Detection Pregnancy Test?2
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 day of your missed period. So, if you see instructions telling you to take the test four days before your expected period, this is the same as five days before your missed period.
Provides early detection of the pregnancy hormone. 77% of pregnancies can be detected 6 days before the missed period2 (5 days before the expected period).
What are the different types of pregnancy tests?
There are several types of pregnancy test: urine pregnancy tests, blood pregnancy tests and saliva pregnancy tests. All types depend on the detection of the same pregnancy hormone, hCG.
Urine pregnancy tests
Tests that use your pee to detect the presence of hCG are the most common type of pregnancy test. You’ll find these on the shelves of your local drug store, and if you go to the doctor wanting a pregnancy test, usually you’ll get a similar type of test there, too. All home pregnancy tests use this type of test, but they may vary in style. Some require you to pee on the stick or pee into a cup where you can then dip the testing strip, with others requiring you to use a small dropper to apply your urine to the test, a bit like a Covid test.
Blood pregnancy tests
Though some home blood tests do exist which can simply tell you if you are pregnant or not pregnant, blood pregnancy tests are more likely to be found in the laboratory and are generally only used for specific circumstances, such as to aid aging of the fetus, or if ectopic pregnancy is suspected. In this case, a blood sample is taken from your arm and sent to a lab to detect the presence, and quantity of hCG in your blood.
Saliva pregnancy tests
The pregnancy hormone also can be found in saliva if you are pregnant. However, the level is much lower, meaning they can generally only be used after the missed period, and their accuracy is lower than for blood or urine test, usually less than 99%.
What are the advantages of using a home pregnancy test?
Home pregnancy tests have many advantages, such as:
- Convenient & inexpensive
- Non-invasive sampling (urine tests)
- Widely available from in drug stores & grocery outlets
- Private & discreet testing
- Results within minutes.
If you follow the instructions correctly, home pregnancy tests are over 99% from the day you expect your period, with some tests being so sensitive to the pregnancy hormone, hCG that you can test from 6 days before your missed period. If you do test early and get a negative result, however, you may still be pregnant as the level of hCG may just not yet be high enough to detect on the test. If you do test early and get a negative result, but still think you could be pregnant, you should test again in a few days time, when the level of hCG may be higher.
How to read a pregnancy test?
When it comes to how to read a pregnancy test, it really depends on the type of test you’re using. Some pregnancy tests are ‘visual’ tests and may show you a plus (+) sign or two lines if you are pregnant, and only a single (control) line if you are not pregnant. The control line is there to show you the test has worked correctly and depending on when you test you a positive line may be faint or dark so can be hard for some to read correctly. That’s why many women opt for a digital pregnancy test, which gives clear results words, such as “pregnant”, ‘Yes’ or ‘+’ and or “not pregnant,” ‘no’ or ‘-‘.
After taking a pregnancy test, waiting for your result can be an exciting or nerve-racking time, and you want to be confident you are interpreting it correctly. Studies demonstrate that the type of test you choose can make a big difference on how easy they are to read. Tests like Clearblue® Early Digital Pregnancy Test give clear results in words. Did you know that 1 in 4 women can misread some types of pregnancy test?3
What should I do if my pregnancy test is positive?
If you get a positive pregnancy test, you are pregnant. However you feel about it, you should contact a healthcare professional about your next steps. As home tests are so accurate, usually your doctor will not need to test again but they can help you discuss your options and ensure you get the care you need for your personal circumstances.
They can also give you support to ensure a healthy pregnancy, including any advice about any lifestyle changes you may need to make, to how access the prenatal care.
While waiting for an appointment, which might be a while, here are a couple of things you can consider doing to support your pregnancy:
- Start taking prenatal vitamins, especially folic acid, if you are not doing so already.
- Make healthy lifestyle choices, such as stopping drinking alcohol, stop smoking if you do, reduce caffeine consumption, and following a healthy diet.
Whether your pregnancy is planned or completely unexpected, your doctor can help support you with the healthcare you need and can even offer advice or direct you to someone like a midwife or a councillor should you need one. You can also seek advice and care at your local women’s health clinic.
Pregnancy tests at the doctor's office
The urine pregnancy tests your doctor uses contain the same technology as home pregnancy tests. Doctor’s pregnancy tests also detect hCG and are over 99% accurate from the day you expect your period. Just like some home tests, some doctors' tests can be used before you miss your period.
As home pregnancy tests are so reliable, your doctor will often not do a second test to confirm a positive test result, though routine practice varies from country to country. If they do a second urine test, often you will have the result in a few minutes. Alternatively, your doctor may do a blood test, either taking a blood sample (blood draw) from your arm, or just a few drops of blood from a finger prick. If a blood sample is taken, it may be sent away to a laboratory, and results will usually take a few days.
FAQs about pregnancy tests
When can I take a pregnancy test?
It depends on the pregnancy test – some even let you test up to 6 days before your missed period.
Can you test too early for pregnancy?
Yes, if you test too long before your period is due, then the levels of hCG in your urine can be too low to be detected by the test, which could lead to a negative result even if you are pregnant.
Should the result be negative, but you still suspect you are pregnant, test again in a few days’ time, or when your period is due.
What are the signs that you should take a pregnancy test?
If you’ve had unprotected sex (especially around your fertile window) and you’ve missed your period, or you’ve noticed other early signs of pregnancy, you may want to take a test.
If you are worried you might be pregnant for any reason, it won’t hurt to take a test.
- > 99% accurate at detecting typical pregnancy hormone levels. Note that hormone levels vary. See insert.
- Clearblue® Early Detection: 77% of pregnant results can be detected 6 days before your missed period.
- Pike J, Godbert S, Johnson S. Comparison of volunteers' experience of using, and accuracy of reading, different types of home pregnancy test formats. Expert Opinion on Medical Diagnostics 2013; 7(5):435-4

How to use a pregnancy test
When and how you can test depends on the test you use, but in this article you will find everything you need to know before starting a test.