I'm not a doctor, but it could be a pimple, an infected hair follicle or something similar.
It doesn't look like herpes.
Is it fluid filled or hard? If it's hard, it may be a wart, but it's not likely that you'd only have one. You posted this several days ago - if you haven't seen improvement, or it's worse, you may want to get it checked. Look around for a low-cost or free std clinic or a Planned Parenthood. They have sliding fee scales so you pay what you can afford based on income.
Thats molluscum contagiosum they tend to go away on their own after a few months as i had it a few years ago from unprotected sex.