You have several different issues.
- Your doctor should have asked you if there was any chance that you could be pregnant. Missing your period for a month could be an indication that you are pregnant.
- The doctor should have given you a pregnancy test before prescribing the depo shot.
- He or she should have explained how important it is that you use protection before going on the shot or any form of birth control because they can cause birth defects and miscarriages.
- The doctor should have explained how the depo shot works. The Depo provera shot is supposed to eliminate periods. It usually take several shots before periods stop but some women stop having periods after the first shot.
At this point, you should take a pregnancy test. The hormone tested for in a pregnancy test is HCG. There is no HCG in the Depo shot so it will not cause a false positive.