Actually, this could be chlamydia, maybe gonorrhea.
Those are both very easily cured with antibiotics, so why not just go get checked? The longer you wait, whatever it is, it might be harder to treat.
AJ
I hope that you did not post under your real name. It is probably best to post using an alias on forum sites.
It does not sound like an STD. It could be prostatitis. Look this up in Wikipedia. Could you have a hernia?
Also, you should always use a condom with new partners until you are comfortable that you are both clean of STDs. How would you feel about yourself if someone gave you herpes and then you passed it on to one of those 2 virgins...