My last period was over a month ago (July 5 th) and as my form of birth control right after that I was put on the depo birth control shot for the very first time. I have also had a very serious kidney infection and am now in the midst of the doctor changing up my medicine for a bladder infection they found when I went in last week. Since I got the bc shot I have not had a period yet. Could the shot really work that fast at stopping my period? Could it be my bladder infection?? Help me as I am really worried!!