hi,

im an 18 year old male and just recently became sexually active a couple of months ago. Recently my girlfriend and I had sex for about an hour and I was unable to ejaculate. After stopping I urinated and felt no discomfort. A couple minutes later she gave me oral sex and I ejaculated, feeling no pain. Right after I ejaculated, I urinated and felt a sharp pain towards the head of my penis and it felt like it was burning. I dont know whether or not this is a UTI, STD, or if infact the pain was just due to some semen mixing with urine as I have heard that the mixing of the two may cause similar symptoms. I was wearing a condom.
Any help would be greatly appreciated