Today’s over-the-counter pregnancy tests are designed to give extremely accurate results. Most brands guarantee accuracy within three percent. However, despite their innovation, pregnancy tests can still give inaccurate results if they are not used correctly or if a woman has a medical condition that throws off the test’s reading of her urine. When you want to know if a pregnancy test is positive can it be wrong, the answer lies in how well you took the test and the state of your overall health.

A number of medical conditions can in fact contribute to a test misreading the hCG level in your urine. For example, if you are taking hormone therapy for a medical condition, the hormones can cause the test to falsely detect hCG in your sample. Likewise, if you are taking medications for conditions like seizures or Parkinson’s disease these medicines can cause your test to come back with a false positive. To get the most accurate result possible when using an over-the-counter test, you should be free from taking any medicines that could affect how well the test reads your sample. If you are on medications for such conditions, it may be best for you to ask your doctor for a blood pregnancy test.

Tests can give also false positive results when they are old and outdated. Like most consumer goods, pregnancy tests have finite shelf lives. If you use a test that is past that date, it could fail to give you an accurate reading. Before you take a test, you should check the expiration date on the package. If the test is past the indicated date, you should throw it away and buy a new one. Expired tests should not be trusted to be accurate.

How Common Are False Positive Pregnancy Tests?

Most brands of pregnancy tests promise to give you a 97 to 99 percent accurate result. If taken correctly, the test should not fail to read the hCG in your urine. However, many women contribute to their own misreadings because they are too eager to take a test. When they rush to test, it is possible that they are experiencing what is known as a chemical pregnancy. Chemical pregnancies are not viable and are usually miscarried within a few days after conception. In essence, no viable fetus develops, and the yolk sac is empty. A woman’s body will miscarry this pregnancy before it reaches its fifth or sixth week.

Women who do not test early and miscarry a chemical pregnancy often believe that they are just having a heavy, late period. However, women who test early and have a chemical pregnancy will get what is technically a false positive. It is positive in that hCG is detected in their urine; however, it is also false because no viable pregnancy exists. Chemical pregnancies and early miscarriages account for about 25 percent of all false positive results.





Women also get false positives when they misread their own results. Pregnancy tests are designed to be easy to interpret. Even so, some women mistake an evaporation line on their test strips as a positive indication of pregnancy. Evaporation lines on a pregnancy test are very faint and often cannot be seen; however, women who do see them may mistake them as the second line on the test strip to indicate a positive result. To avoid this, women should allow the test to sit for several minutes before trying to read the results. A positive test will in many cases show very visible lines in the test strip’s indicator windows.

Faint Positive Line On Pregnancy Test

Some cases do exist, however, when a test will show a faint line in the indicator window. These faint lines can be difficult to interpret, as noted, because they could be just be the result of evaporation. When a woman sees faint lines on the test strip, she should allow the test to sit for a few minutes longer to see if the line will become more visible. If it does not, she should test again to know for sure if she is pregnant.

Many over-the-counter test instructions say that the faintest of lines should be interpreted as a positive sign for pregnancy. If several tests keep giving faint lines, a woman can try different brands of tests for better results. If she is still not convinced, she should ask her doctor for a blood test for the most accurate results.

Faint lines also may occur because the test is old and the film over the indicator window is compromised. Before buying a test, a woman should check the package for signs of tampering. She should also check the test’s packaging to find out the expiration date. She should only use tests that are still within their indicated shelf life dates.