I think i might have a STD....

Im scared.... I havent had sex with anyone in a very long time. The last time i had sex was in may. With my ex. And he didnt have anything we both got checked. And it came out fine. I did have sex with 3 other people. But that was way before that. And there tests were fine too.

I have a pimple on the outer side of my vagina lips. Its been there for about a month or so. It hurts and it feels sore. Its about the size of a jelly bean.

Should i go to the doctor. The thing is i didnt get it till this month.