I had an ulcer 6 months ago on my penis, it was painful and it healed on it's own. I have been in sexual contact with one person and she is symptom less and never have had any symptom of any std. I had contact with her about 8 months before this ulcer! Now I have seen a small healed scar of that ulcer which is asymptomatic. And does not have any other symptoms no fever nothing after that ulcer. But I was anxious about the scar. What could be the probable diagnosis and is there something to worry ? What should I do now?