Progesterone is a natural progestin and can play a role in replenishing progesterone. Taking progesterone followed by an early pregnancy test will not affect the results of the early pregnancy test, because the early pregnancy test is used to detect the level of HCG contained in a woman’s urine, which doubles in her body when she is pregnant. If the progesterone and HCG levels are found to be low, progesterone medication should be taken under the guidance of a doctor, such as oral progesterone or intramuscular progesterone injections. It is recommended that women take several early pregnancy tests or routine blood tests for HCG to determine whether they are pregnant.