I don't know if iam pregnant or not am i

i got put on contraceptive birth control last summer and i was bleeding for along time and i stoped i guess then this month i bleed for a week so i guess it was a period then a day later i had unpertected sex then two days later i started to bleed a little and watery then the next it slowed down and i had unpertected sex and i was bleeding mild and watery with cramps..................whats going on