What Causes Penile Irritation And Painful Urination After Receiving Oral Sex?

I was dry humping two nights ago. The next day I had irritation with my penis and it hurt to pee. Today has been better. Less irritation and the constant having to move my penis around is better and urinating isn't as bad. I have also been experiencing gas problems the past few weeks and yesterday at my doctors appointment he ordered a urine test. I didn't mention my pain because I figured it was just from the friction and pressure. But I'm just curious what someone has to say. Because she did perform oral sex for just about 5 seconds and I told her to stop. I'm just curious if you can experience symptoms of STDs or STIs within 6 hours. My problem seems to be getting better like I mentioned before