Pregnancy tests look for a hormone called human chorionic gonadotropin (hCG), which the female body releases shortly after the fertilized egg is implanted into the uterine wall. The Mayo Clinic recommends waiting one week after a missed period to take a home pregnancy test, though the best home pregnancy tests can confirm pregnancy earlier than this. If you want a result early in your pregnancy, then it is important to look for a test that is very sensitive to hCG levels.
Doctor Administered Blood Test
The Mayo Clinic recommends a doctor administered blood test as the method most capable of detecting early pregnancy. Like home pregnancy tests, the blood test identifies hCG. It can identify levels of the hormone at or above 5 mIU/ml (milli-international units per milliliter), which signifies a pregnancy. The results can take a few days as the blood sample has to be assessed by a lab.
First Response Early Result Pregnancy Test
A test conducted by Consumer Reports found the First Response Early Result Pregnancy Test to be the most reliable home kit in the very early stage of pregnancy. This test is recommended if you're looking to detect a pregnancy soon after fertilization. It has been documented to identify hCG levels as low as 6.5 mIU/ml, which is standard three weeks after fertilization according to the American Pregnancy Association.
Clear Blue Easy Pregnancy Test
The Consumer Reports study also recommends the Clear Blue Easy pregnancy test if you're looking to detect pregnancy soon after the fertilized egg implants itself. This test detects hCG levels at 25 mIU/ml, which appear three to four weeks after fertilization.They praise this test for its sensitivity to hCG and like the test's visually intense and easy-to-read results.
