Definitely see a doctor, hun. Can you try and better describe to me where it is? Is it on your groin or back behind your testicles directly between your legs. Does the lump become more noticeable when you cough or strain? Try palpating it (touching it) to see if it bulges out more when you cough or bear down like you're straining to go to the bathroom. If it does, chances are good it's a little hernia, which is basically simply a weakness in the muscle that allows some other tissue to bulge through. That's what you feel as a lump--the other tissue bulging through. Hernias in that area are very common, and they can either be repaired or sometimes just left alone.