What may cause a “false positive or false negative” while using a pregnancy test?
Most medications will not interfere with pregnancy tests, unless they are some type of fertility drug that contains hCG. False negatives may also occur if the test is done too early in the pregnancy, so it is generally advised to take another test one week after a negative result if you suspect you are pregnant or if the menstrual cycle has not yet started. If negative results still occur, see your doctor for a more accurate blood pregnancy test.
