7 Reasons Why Pregnancy Test Can be Wrong

Feb 10, 2010

Many women use home pregnancy tests to find if they are pregnant as early as possible. Home pregnancy tests are easy to use, inexpensive and are claimed to be 99 percent accurate in determining pregnancy.

However, there are cases when the results of home pregnancy test can be false negative or false positive. What are the reasons that can make pregnancy test give wrong results?

  1. Bad Quality Test. When you buy a home pregnancy test, always check the expiration date. The test that is expired or is badly stored can give false results.

  2. Incorrect Use. Most tests require you to use the first morning urine that you should collect in a cup. If the cup is not clean and there are traces of soap or detergent left in a cup, the results of the home pregnancy test may also be incorrect.

  3. Too early. Many women are impatient to know the results and can get false negative result because they did the test too early. If you preformed a home pregnancy test on a first day of the missed period you have 80 percent of having the right result. This happens because the level of the HCG produced during pregnancy may not be high enough to give positive results if it performed too early. Specialists recommend waiting a week after a missed period to check the results again.

  4. Medicines. The results of the home pregnancy test may also be false if you take certain medications. These include medications containing hormones, anticonvulsants, tranquilizers, diuretics, promethazine, and drugs to treat Parkinson's disease.

  5. Miscarriage. There can also be the case that the home pregnancy test is negative if you had miscarriage at an early stage of pregnancy. Call your doctor especially if you have other signs like abnormal bleeding.

  6. Wrong Interpretation. In some cases, women just misinterpret the results of the home pregnancy tests, especially when they see a faint line on the test. In this situation it is better to use two different types of pregnancy tests to check the results.

  7. Tumor. In rare cases, the false positive results of pregnancy test are caused by a tumor in the reproductive tract. The tumor can produce HCG and give false results. There are also other symptoms like vaginal bleeding, abnormal abdominal growth and severe vomiting.