i doubt your pregnant, you dont need any precaution like the pill, irregular bleeding is a very common side effect, i get this constantly now im not having it again it annoys me so much
Irregular bleeding is actually a common side effect. Anyways. The shot is supposed to be 97-99% effective, and since you were also using a condom (even though it broke) the chances are unlikely that you will get pregnant.
I have been on depo provera before... I believe that you are not suppose to get periods at all??... It may be spotting which could be an indicator of pregnancy... buuuut then again if you are birth control it makes it unlikely....