What Causes Severe And Persistent Cramps In The Stomach?

ive been on the depo provera shot for a while got my 3rd shot in december, ive had cramps for the past week, and flutters in my belly, the last shot before the thrid one i was 2 weeks late due to the job i work, and was curious could i be pregnant, cramping last most of the day not unbearable, just uncomfotable, ive went to the emergency room once because my cervix were enflammed and really worried about pregnancy, the clinic took a pregnancy test but the day before the condom broke. need some advice!