Confused and need help

Wednesdays and Thursdays i missed both my birth control pills and didnt realize it till Friday afternoon me and my boyfriend had sex Thursday and injected into me...its Sunday and im lightly blood due to the pill i take im not supposed to get my period my doctor said ill get it maybe twice a year but its never happened before i know its extremely early but could this be because im pregnant or because i missed 2 days. I need some advice please and thank you.