You should wait to take a pregnancy test until the week after your missed period for the most accurate result. If you don’t want to wait until you’ve missed your period, you should wait at least one to two weeks after you had sex. If you are pregnant, your body needs time to develop detectable levels of HCG. This typically takes seven to 12 days after successful implantation of an egg. You may receive an inaccurate result if the test is taken too early in your cycle. Here are some signs that you should take a pregnancy test.