 [ Symptoms ] i am on birth control but i started spotting a few days before my scheduled period is this common  i also had unprotected sex last night the day before my period is supposed to start and so far i have not seen any sign of my period is there a chance i could be pregnant [ Disease ] yes women can spot on their birth control pills depending on their particular dosage etc if this happens on a regular basis your medical provider may need to make a dosage adjustment birth control pills offer excellent contraception you are unlikely to be ovulating the day before your period so pregnancy would be unlikely as well