hi doc. i am 20 years old. im afraid im pregnant. i had sex for the first time last month, aug 14. during that month, my LMP was Aug. 3. then i had a very unusual bleeding on Sept. 1. it started as brown, then after two days, it became reddish just like my normal menstruation although i didnt consume a pad for the whole day. it was not just spotting because it flowed. then it turned into brown again and all the bleeding lasted for 9 days. i dont have sore breasts, i dont have nausea and vomiting. is it just my body adjusting after my first sex? or am i pregnant?