I just had unprotected sexual intercourse with a woman significantly older than I am. Soon after we were done discovered she was not only married but had a child who was 15 years in age. This scared me and I demanded she tell me if she had an STD or not. She claimed and promised no, but that was not good enough for me. Where the shaft meets the penis a red rash formed and soon following it was a what appeared to be a tiny whitehead (zit) I tried many time to pop it and finally gave up. The area is slightly uncomforatable, but very concerning. What should I do ?