text: First of all, you most likely weren't pregnant.  It is very rare for a woman to have a normal menstrual cycle during pregnancy (though not impossible).  You should go to your doctor and ask for a pregnancy test if you have any doubts.  Depo Provera is changing the way your body works, and you will likely experience some strange effects from it at first.  The first time I took Depo Provera, my period became very heavy and lasted a very long time.  After that, I had no side effects.\n\nDepo Provera uses progesterone to stop your ovulation.  Progesterone is less dangerous to a fetus than estrogen, which can cause abortion, sexual complications, etc in the unborn child.\n\nIf you are pregnant, you will need to consult your OB/GYN and let him or her know that you have received this injection so that tests can be done to ensure the safety and development of your child.\n\nAs for the effects you are having right now, ride them out.  If they don't go away, consult your doctor before the next injection.  You may have to change the form of birth control you are using.