Will hormones in the pill affect the results of a pregnancy test?

Someone asked us:
If I am on the pill, and I had to take a pregnancy test, would the hormones in the pill affect the result of the test?
Nope — pregnancy tests are 99 percent accurate, whether or not you’re on the pill or any other form of birth control. The hormone that a pregnancy test detects in your urine is called human chorionic gonadotropin (hCG), and it’s only produced during pregnancy. It’s not found in hormonal birth control (which contains the hormones progestin and estrogen).
Taking a pregnancy test correctly usually means waiting to take it after your missed period, although some brands can be taken a few days before. You can read the label on the box to see when it becomes effective.
-Nina at Planned Parenthood