3 Little Bumps On My VLip

I have these little red bumps on the inner lip of my vagina. They burn like hell when I pee! They showed up a day or two after I had sex. They almos look like little pimples, but theres no white head & no white on the top of them. Just bright red. Only when I touch them every now & then do they hurt besides when I'm peeing. Could this be an STD? Or just from rough sex?