What Causes Penis Glans Spots With Redness After Unprotected Intercourse?

Hello, i noticed lots of people asking about the red spots on the tip of the penis. I noticed a couple of days ago. I had small red dots. Now they seem 2 have moved around. I am uncircumsized. I had unprotected sex with my girlfriend. that's when I noticed it. I have been taking amoxicillin. Wonder what it is that I have and how long till it goes away