 [ Symptoms ] 17yr missed period in april spotted in march nothing in june pregnacy test negative on depo shot last year hello  my daughter is 17 she has been sexually active and claims a condoms was used in the act she did not receive a period in april and than spotted in march no period yet for june she did take a test and it came back negative she was on the depo briefly  she only took two shots and than stopped her last shot was last year i want to say in july 2012 please note that she had been getting regular periods up until april when she did not receive one [ Disease ] i am not sure if you are saying your depo shot expired 3 months ago or if the last time you had a booster was 3 months ago if your depo shot expired 3 months ago then you can absolutely get pregnant by unprotected sex the depo shot is not a permanent solution depo provera birth control lasts roughly 14 weeks in a woman is system before being completely ineffective but the shot must be received every 12 weeks to maintain full protection