IT is highly unlikely to be herpes or any other STD for that matter. It is very likely a clogged hair folical(folicalitis). Just be sure to soap up good down yonder and really try not to pick at it. Just put some over the counter anti bacterial ointment (though use very little at first as some people have an allergic reaction to the ointment on genital tissue.) A warm wash cloth compress is another way to alleviate/unclog the pore, possibly followed up with 15 minutes (no more) of "indirect" icing.

Anyway, it if were herpes it would more than likely be closer to your penis or scrotum and it would be more along the lines of a painful, raw sore.

Last but not least, relax. I've been in your shoes man. I thought I had a STD and I SCOURED the internet for info and freaked myself out. However if you just can't get it out of your mind, go to a doc have him check it ou.

Oh, and pull your pants up dude.