Not all pregnancy tests are created equal. Early-Pregnancy-Tests.com provides the most sensitive pregnancy tests on the market. The more sensitive the test, the earlier the opportunity to detect pregnancy. Our tests can detect pregnancy even with a small amount of hCG in your system. Concentrations of hCG are reported in milliInternational Units (mIU) or amounts equal to 1/1000th of an IU per milliliter. Pregnancy tests with a sensitivity of 20 mIU/ml are more sensitive than tests with 50 to 100 mIU/ml.

E.P.T. 40 mIU/ml hCG
ClearBlue Easy 50 mIU/ml hCG
First Response 100 mIU/ml hCG
Answer 100 mIU/ml hCG

At 20 mIU/ml, high sensitivity equates to early detection of pregnancy. That means you can begin testing accurately as early as six to eight days after conception - well before your first missed period. NOTE: Conception may take place several days after date of intercourse, so the date of intercourse should not be viewed as the necessary day of conception.

source: early-pregnancy-tests.com