If it were me I would head to the Dermatologist and have it checked out. I'm not a Dr., but I do know that my Dr. told me that melanoma can re-occur at any time (seeing as how once you have had it, you are more subceptible (sp?) to developing it again. It may very well be nothing, but why take that chance? To me it's just not worth risking, but I'm also probably a little paranoid when it comes to mm.......I don't ever want to have this expierence again. That said, I'm sure yours will turn out to be nothing
Best of luck to you!