Birth control confusion

I started taking birth control 5 days after taking it i had sex we used a condom after we were finished i thought it broke he put water n it after nothing leaked so it didnt break when he pulled it off tho something dipped off it i am suppose 2 start and i was bleeding really light like so light it wont even get on my pad and then it quit im so confused rn is it my period or am i prego is this how my period is suppose 2 b on low estrogen birth control pills