Had unprotected vaginal one night stand over a year ago. Sex lasted for maybe 5 to ten minutes. Had myself tested 14 days after for chlym and gohn. through urine test and came back negative. Had a swab test 2 months after that and it was negative. Now over a year later a small bump appeared on the left side of my penis glan that looks like it has a small indent in the centre. It is about 1mm in diameter. It doesn't hurt or itch and feels a bit hard to the touch. The only thing that comes up when i search online is syphilis but it looks nothing like the pictures and it's a full year since the encounter. It's been the same size and shape for about a week now. Any ideas what this could be?