Uh oh...

Hi i think i did the dumbest thing every!! I'm 15 and I've always been really careful, but today my gf gave me oral when she had a cold sore. I;m really scared and so is she. We didnt think it would transmit through mouth to genitils but after searching the web i foudn out that it is very much posible! I'm really scared i don't know if i just got genital herppes or not please help! Is there any cure? within like the first few days? Should i go see a doctor? I really need answers thank you!!!