I think I caught a std. Any thoughts

image

Hello, had sex in April and noticed this red bump a week later. Only symptoms are minor itchiness/sting once in a while, the bump in of itself, and the fact that if I apply enough pressure to the bump a white-ish substance comes out over time. Symptoms have never gone away. I think it never went dormant. 2 weeks in April later tested negative in: Gonorrhea, Chlamydia, Hepatitis C, Hiv 1/2, and Syphilis. Any food for thought what it might be. Don't know how photo file is too big by the way.