Pimple-like things, release puss like pimples

I have had these things that seem to be like pimples on my inner thighs and between my scrotum and anus. They produce puss sometimes when squeezed, and other times won't release anything at all.

These started about 4 or 5 years ago, and when I went to get an STD test, I was given all negatives, so I figured they'd just go away, but they haven't. I did make some mistakes in having a lot of unprotected sex when I was a teenager, so if you have any idea if this is an STD or not, I'd be appreciative of the response.