For the past two weeks, Every time after I masturbate (I am a male), I get a burning sensation around the base of my penis and the root of my penis. The burning can last for a day or two and is more annoying then unbearable. Gold bond powder helps a little, as does neosporin. My last sexual encounter was over a month ago (protected), I have since been checked by my Dr. for Chlamydia and Gonorrhea, those test's were negative and I have had no sores (like Herpes) at all. What is the problem? Should I be concerned?