Hi, i'm 17 this year and i had unprotected sex with my boyfriend 2 weeks ago. A few days ago, i started to have my "period". The blood that came out was dark red and looked like the blood that was discharged when i had my periods. But this time it only lasted about 1 day or less. I'm really worried that i'm pregnant. My periods are always regular and this had never happened to me before. Could anyone help me here? I'm really at my wits end.