Painless Chancres-all the Std Tests, No Answers!

About 3 days after a sexual encounter, I had 4 chancres which looked like syphilis, no blister and circular scattered at the base of the under shaft. It was painless and shallow in the skin. I applied neosporin and they went away in a week. A few days later it came back in various other areas on the shaft. Its stages were:
1. A red irritated dot on skin 2. Progressed to a dark-red circular scabbish crackling of the skin, looked like syphilis 3. Slow healing rate, three weeks later, as it tries to heal and skin scales off, the scar remains and is dark-red with minor "pinhole" cracks in it.
Three weeks later I went to the doctor, took a syphilis test, with normal results. I took doxycycline for a week as it seemed to be trying to heal, and eventually the dark scars turned to normal skin. A week later the last chancre that formed before came back, so I immediatly took a 2 week doxycycline med and got a herpes test. The test came back normal and after the 2 week treatment, they still remain and now over three weeks my under shaft has a 3/4 inch diameter dark-red circle of seemingly scar tissue with little pin holes in them. Ive stopped treating the problem and it seems to be healing at a rediculously slow pace, almost like it stopped. When I pour alcohol on it, its has a 8 second delay before I feel a slight pain. I think another patch of it is forming on the shaft and I am getting fed up. Anyone have any experience with such problems? Since the 3 ive seen doctors have no answers for me and are suggesting I have a biopsy (removed skin analysis....I dont want them carving into my tool leaving deep scars)