10 weeks ago I received unprotected felllatio from a stranger. 2 days later a small raised black/dark red bump appeared on my penis head just below my opening. It hasn't changed for 10 weeks - round, < 1/8 inch, slightly raised, smooth, not hard or soft - sort of like a firm blood blister. No other symptoms - no pain, discharge, etc. It doesn't appear to fit any traditional symptoms -- syphillis chancres appear to take at least a week to appear and then ulcerate -- this was two days and hasnt changed for 10 weeks. It doesnt look like a wart. Any input appreciated. Thanks