Hi, I am a 22 year old female, and recently had sex with my boyfriend for the first time. we used protection, but several days later I noticed a slight irritation around my vestibule area, and just today I looked much closer, and there are two, nearly symmetrical sores near my vagina. One is much more painful than the other, and is much like a canker sore. This couldn't be an STD if we used protection could it? Do I need to see a doctor?