Me and my bf had sex 3 times already and I'm on birth control and I've been taking the pill correctly everyday for 6 months and I'm not on antibiotics or anything he also pulled out every time even though pulling out doesn't work my period was supposed to come Sunday and it came yesterday but it only lasted for a couple hours there was a lot of blood like a period but then it just stopped after awhile I understand that birth control can mess us your cycle but mine is alway comes on the same day and lasts about 3 days can having sex mess with your cycle and am I just overreacting about being pregnant