Whether it is or not, if there's a chance you could have one anyway then pop along to your local GUM clinic (with no unprotected hanky panky in the meantime) for some checks so, if you do have something they can get it sorted.
As for the rash, is there anything you could be allergic too or anything which could have irritated it such as shaving or heat? It's very hard to diagnose any kind of rash without far more details and seeing it and very unlikely you will get a clear answer on a website.
Maybe worth a trip to your GP to check both out at the same time?