Has anyone else experienced this or know what this is? I had sex about two months ago and got tested and everything came back negative (the partner I was w was also negative); also I started a birth control and took myself off bc of crazy side effects.

It looks like heat rash or razor burn.. 

Definitely not genital warts or herpes...

They don't automatically check for herpes you have to request it

I had something that looked a lot like that. It would cut so bad at times and others days nothing. Still comes and go's my doctor told me that sit bacteria from us shaving and so on. They can give u antibiotics to help it if it doesn't work then then can remove it if it's bad

Skin tags totally normal down there as your underwear rubs :) I have a couple too. You can have them removed if they bug you.

My best guess is gential warts, which you don't necessarily test positive for every time. Definitely get it looked at.

Def need to see a doctor about that could be an allergic reaction.