Hi i'm a 17 year old female, i had sex for the first time with my boyfriend about 3 weeks ago, it was protected, i've had my periods since then, they only lasted about 4 days but my breasts have become really large, i have days where i eat a lot, and some days where i'm turned off food, i get really bad stomach pains quite a lot of the times, i often throw up but sometimes just gag, i feel sick immediately after waking up and eating ( most times), i also get really bad headaches that pound and dont go away, i get dehydrated easily and feel quite dizzy most of the time. what could this be ? %-)