Day to take a pregnancy test

The pregnancy test should not be done before the delay of menstruation, nor before 15 days have passed since sexual intercourse, in order for the result to be reliable.

If the pregnancy test is performed too early, the levels of hCG hormone (the pregnancy hormone) may still be so low that the test cannot detect them. This would produce a false negative result, as the woman would be pregnant, but the test would not be able to detect it.