I am a 17 years old male, have a girlfriend (also 17). Recently in the past few weeks, we had a bit of heavy petting, and even went up to oral sex (there were no intercourse). Of course, being cautious teenagers, I put on a condom before any form of sexual contact. Our most recent sexual experience was about a week ago, and today some time in the afternoon, I had an erection that lasted for one or two minutes (i did not masturbate). After which, I went to the toilet to pee, towards the end of my pee I tried to force out a bit more pee and I noticed a white, semen-like discharge. However, I knew it was not semen as it was not sticky but it looked opaque white. The amount was about a tablespoon full. I googled and did lots of research and it seems to me that I have contracted Chlamydia or some sort of similar STIs. I don't want to visit the doctor yet because everything seems so uncertain, can any health professionals please advice me?