Is a Positive Pregnancy Test Always Accurate?
Taking a pregnancy test can be a nerve-wracking experience. Knowing if you can trust the result is important! Find out how accurate pregnancy tests are, and if there are certain types that are more accurate than others.
To understand how accurate pregnancy tests are, it can be helpful to first understand how they detect pregnancy. A home pregnancy test works by detecting a hormone that is only present in urine during pregnancy. Once a fertilized egg implants itself into the uterus, it sends a signal to the mother’s body to start producing this hormone, called human chorionic gonadotropin, or hCG for short.
This hormone builds up rapidly in the early days of pregnancy, quickly becoming detectable in the urine with a home pregnancy test. Some test strips will require you to collect urine first in order to test, while others are able to simply be directly under the urine stream to collect a sample.
Both of these types of tests are 97-99 percent accurate when taken according to manufacturer directions at the proper time, according to this article from MedlinePlus.
What are some reasons I might have a false negative test?
The most common reason for a false negative result when taking a home pregnancy test is simply testing too early, before hCG levels have risen to detectable levels. Other reasons for false negatives include rare faulty rests, or failing to follow directions correctly.
Following the directions, testing after your missed period, and using quality pregnancy tests can all help decrease the chances of a false negative result.
Are there ever false positive pregnancy tests?
A false positive pregnancy test is rare. However, some women who test early and see a positive result and then get a period anyway, leaving them wondering if they had a false positive.
Sometimes, a fertilized egg might implant and begin to produce hCG in the mother, only to quit developing immediately. Miscarriages that occur in the first week of pregnancy are often referred to as chemical pregnancies. While not a true “false positive” test, chemical pregnancies can be both confusing and disappointing.
What if the test is negative, but I still have not had my period?
If you are waiting for a period that has not arrived, but are still seeing negative home pregnancy tests, it might be time to call your care provider. Sometimes, hCG levels may be slow to build due to various reasons. Other times there may be an unrelated reason for your delayed period. Either way, if you are experiencing unusual or extra-long cycles while trying to conceive, it is worth having a conversation with your provider.
Home pregnancy tests are most accurate when taken after you have missed a period. However, early detection pregnancy tests can sometimes produce a positive result as early as 5 days before your expected period.
If you have taken an early detection test before your missed period and it is negative, you can always wait a day or two and test again. In a normal early pregnancy, hCG doubles about every 48 hours.
Once you are a week late for your period, a negative test result has a very slim chance (about 4%) of being a false result, and you are most likely not pregnant.
What should I do if I do not think my test results are accurate?
If you are experiencing pregnancy symptoms or are late for your period and are still seeing negative test results, you may be wondering what to do next. If for any reason you are concerned about your cycle or not convinced that your home pregnancy test results are accurate, see your care provider right away.
A blood test can be ordered to confirm if you are pregnant or not, as blood tests are able to detect even lower levels of hCG than home pregnancy tests. If you do have detectable levels of hCG in your blood, follow-up testing can help determine if those levels are rising at a normal pace, or if there might be a problem with the new pregnancy.
If I have a positive pregnancy test at home, does it need to be confirmed with a blood test?
While a positive test is almost sure to be accurate, you can request a blood test to confirm your results from your care provider if you would like the peace of mind. If you have been receiving fertility treatments or have a history of pregnancy complications, you may already have a plan in place to track your hCG levels throughout the early days of your pregnancy.
Overall, home pregnancy tests are incredibly accurate, very affordable, and the first choice for most hopeful parents in determining if they have conceived or not. Whether you choose to use a collection method with a simple test strip, or a midstream test that does not require collection, you can be confident in your results if you have followed directions and waited for an appropriate time to test. Remember that you can always test again after a day or two if you have received an early negative test!