Family Planning Council: FAQs How long does it take for the pill or Depo-Provera (the shot) to work? . Depo-Provera can stay in the system of a woman for six to eighteen months after
Ask Emma Answers-Birth Control/ EC The hormones from birth control pills only stay in your system for about 24 hours .. "How long does it take for the hormones from the patch to leave and
Contraception Questions How long does the morning after pill stay in your system ? .. lack of bleeding might have been a sign that you were pregnant and that the EC didn't work.