Early Pregnancy Test: When Can You Get an Accurate Result?

Home pregnancy tests work by detecting the level of human chorionic gonadotropin (hCG), a hormone produced in early pregnancy, in your system. These levels can be present as early as six to eight days past ovulation, depending on when conception takes place.

Test Sensitivity

• Some home pregnancy tests are more sensitive than others and can detect smaller amounts of hCG present, and, thus, are able to detect pregnancy earlier. The most sensitive tests on the market can detect as little as 20 mIU of hCG, the level present in the average pregnant woman at about seven to eight days past ovulation. Most home pregnancy tests can detect between 50 and 100 mIU of pregnancy hormone, about the average levels of a woman whose period is one to two days late, or approximately 12 to 14 days past ovulation. The earlier you test, the more likely you are to receive a false negative.

Conception and Implantation

• The body does not begin to produce hCG until the fertilized egg implants itself in the uterus. This can take several days after conception and will increase the wait for an accurate pregnancy test. Every woman's body is different, but the average woman will begin to show levels of hCG at greater than 20 mIU at about 10 days past ovulation, or about six to seven days past implantation.

Missed Period

• The most accurate to time to test with a home pregnancy test is right around the time that your period was due to start. Some home pregnancy tests claim that you can get results much faster, but these are not always accurate. After ovulation, it could take a day or two for conception to happen, then it could take several days -- or even as long as a week -- for implantation. If you test before your missed period and get a negative result, you should test again if your period does not start on time.