Hi Gabrielle, Welcome to HealthcareMagic Forum.
Most women who have taken a shot of Depot Provera
will have some changes in their menstrual periods including irregular and unpredictable bleeding or spotting, increase or decrease in menstrual bleeding or no bleeding. But it is effective only for 3 months and the shot has to be repeated every 3 months to prevent pregnancy
However, it takes a minimum of 9 to 10 months to get pregnant after getting the last shot. To alleviate your fears get a Urine Pregnancy test done and consult a Gynecologist.