I have an ulcer that has formed in my pubic area right above my penis. My doctor has tested and Ruled out any std including herpes or syphilis. Could it be related to anything else and why does it not want to heal. I have had it now for two months. I don't have a history of diabetes and it started out as a small pimple and has grown to an 1/4 inch in size. It is open and bleeds very little and on occasion forms a scab which usually falls off when I take a shower. Needless to say I have not had sex for two months now and don't want to have sex until I find out what is causing it and get rid of it completely. I hope one of your experts can help me.