Most home pregnancy tests are reliable, for example Clearblue's tests have an accuracy of over 99% from the day you expect your period, and while it's possible a test showing a negative result is wrong, particularly if you're testing early, getting a false positive is extremely rare.
Because hCG is usually only present in your body when you're pregnant, false positive results are incredibly rare. If you use a reliable pregnancy test, like Clearblue, you can be over 99% certain you're pregnant if you see a positive result.
Know this: All Clearblue® pregnancy tests are over 99% accurate from the day you expect your period. False positives very rarely occur, and are often due to medical conditions or certain medications. False negatives, while more common, typically occur due to testing too early or drinking too much liquid before testing.
This usually ranges between a couple of minutes up until 10 minutes later. If you see a positive result beyond this time frame, you may be left second-guessing the results. However, always remember that a pregnancy test result is only accurate within 10 minutes.
“False positive pregnancy tests are rare and occur less than 1 percent of the time,” confirms DuMontier. Generally speaking, there will be a contributing factor if you're seeing a false positive pregnancy test. If not, you can assume the test you've used is faulty in some way.
That's rare. But it is possible to get a positive result from a home pregnancy test when you're not pregnant. This is called a false-positive. A false-positive might happen if you had a pregnancy loss soon after the fertilized egg attached to the uterine lining.
For the most part, pregnancy tests don't get darker as they go along. “These tests are designed to be read usually within 10 minutes of you doing the test,” says Dr. Demosthenes.
Clearblue Digital Pregnancy Test with Smart Countdown
If you take the test on or after the first day of your expected period, the results are 99 percent accurate. That said, the test is sensitive enough to detect pregnancy five days before a missed period.
How to identify an evaporation line on a pregnancy test? In early pregnancy, there may be very little hCG in the urine, and the positive line may be faint. But even a faint positive line has color, and this distinguishes it from an evaporation line, which is colorless.
Although both Clearblue and First Response are trusted consumer brands, First Response has the slight edge. Their tests can be administered earlier than Clearblue (up to six days before your expected period date) and the results are 97% accurate on the first day of your missed period.
Clearblue Early Detection Pregnancy Test provides early detection of the pregnancy hormone. 71% of pregnancies can be detected 6 days before the missed period (5 days before the expected period) and 94% of pregnancies can be detected 5 days before the missed period (4 days before the expected period).
The UK's COVID-19 testing programme uses real-time reverse transcription polymerase chain reaction (RT-PCR) tests to detect viral RNA. Public Health England reports that RT-PCR assays show a specificity of over 95%, meaning that up to 5% of cases are false positives.
Pregnancy Tests
Can be used 5 days before your missed period (which is 4 days before your expected period). In lab testing, pregnancy detection rates were: >99% one day before the expected period, 98% 2 days before, 95% 3 days before, and 75% 4 days before (5 days earlier than your missed period).
The test is over 99% accurate from the day of the expected period8. 71% of pregnancies can be detected 6 days before the missed period (5 days before the expected period). The Clearblue Rapid Detection Pregnancy Test is over 99% accurate at detecting pregnancy hormone and is also easy to use.
What level of hCG can pregnancy tests detect? Generally, most home pregnancy tests claim to detect hCG levels from 25 mIU/ml. However, some tests, such as the Clearblue® Early Digital Pregnancy Test and the Clearblue Early Detection Pregnancy Test, are so sensitive they can detect hCG levels as low as 10 mIU/ml.
Most home pregnancy tests are reliable, for example Clearblue's tests have an accuracy of over 99% from the day you expect your period, and while it's possible a test showing a negative result is wrong, particularly if you're testing early, getting a false positive is extremely rare.
In general, the best time is when you have your first morning pee. However, some pregnancy tests are sensitive enough to detect HCG no matter what time of day you take the test.
For your result to be 'Pregnant' (positive) there must be a blue line in the control window and a '+' symbol in the result window within 10 minutes of testing. It does not matter if one of the lines that make up the '+' symbol is lighter or darker than the other; the result is 'Pregnant'.
Any positive line, no matter how faint, means your result is pregnant. Levels of hCG in your body will increase over the course of your pregnancy. If you test early, your hCG levels may be still be low and you'll see a faint positive line.
HCG is at its highest level in the morning when urine is fresh and not diluted by the liquid you drink during the day. If you test in the afternoon, your urine may not have enough HCG to detect.
Depending on when you're taking it, there might be some benefit in taking one test and then a second one (again, a few days later). But cleaning out the entire drugstore shelf to be really certain? Yeah, no. Stick with two or go see your doctor to put any uncertainty at ease.
Home pregnancy tests can be up to 99% accurate. However, in some instances, they may produce a false-positive result. Incorrect test usage, previous abortions and miscarriages, and some medications may lead to a false-positive pregnancy test result. People should always see their doctor after a positive pregnancy test.
It's possible to get a negative pregnancy test result followed by a positive result, especially if you tested early. This is because hCG levels rise rapidly in the first few days after implantation. It's also possible to get a positive test result followed by a negative result.