Do you think i could i be pregnant?

ok so i got the depo shot the end of may and was due for another the end of august (which i didnt get). it worked fine until the beginning of july i began my period for an entire month. from july 3rd to july 26th!!! which my doc told me was normal since i wasnt bleeding alot. i didnt want to get another becuz i was scared to have a period for so long again. but anyways, i havent had another period, but i have had unprotected alot since my period ended in july. and i have had a close friend get pregnant on the depo shot as well... should i wait a little longer then take a home test? but also the catch is... my bf got a vasectomy over a year ago when he and his ex no longer wanted more kids. he got it before deployment and never went back to get tested to see if it worked.... i am so ter brained right now. i just need insight from someone!!! thanks!!