Hi I am 15 years old and about 6 days ago I has unprotected sex with my boyfriend, but he pulled out. It's been 6 days since then, and today I was at school and went to the bathroom and found brown stuff in my panties, I wiped it off and nothing came out the rest of the day. Then my stomach has been gurgling and growling like crazy, my boobs are sore and have blue vains popping out of them and they are really pointy. I also haven't had a big appetite at all. Could I be pregnant?