Had unprotected sex, negative STD, red and inflamed penis. Should I be concerned?

hi i would really appriciate it if you could help me with a problem i have. I had unprotected sex 9 weeks ago and was concerned i would have contracted an STD i went for a full blood test urine sample and swab test 6 days after the event and it all came back negative. i then went back 2.5 weeks after and had JUST a urine test and this also came back negative. 6 weeks ago i noticed i had a small white spot on the shaft of my penis painless no redness and it was not tender about 2.5mm in diameter. it stayed like that for 4 weeks and last week i noticed that it was red and inflamed and tender but not an ulcer just a spot as before no fluid was excreted. It looks as if it has been caught and took the head off the spot and it has aggravated it. the only STD that slightly resembles this is syphilis but i was wondering it is not a sore or a ulcer it is a spot and also it was a small white dot to start then weeks later turned in to this red spot which is inflamed. should i be concerned?? thank you