Please tell me what is wrong with this.?

started having a bit of a dull pain in my lower molar on the left side two weeks ago. I've had an infection with that tooth before and it's been confirmed that I don't have it again. I started having what felt like a UTI and remembered that my dentist said that if left untreated long enough, a dental infection can spread to other parts of your body. I've had UTI symptoms for about a week with little improvement. I went to the doctor who said I don't have an UTI, with lab results as proof. However, they're now testing for any STDs and I'm scared out of my mind to find out what the results are. I've only had unprotected once and I know it takes just the one time. The thing is that the last time I had was well over a year ago and I haven't had any signs of an STD to this day. It's just the thought of it that is making me extremely worried. Is there any possible way that it could be an STD with no noticeable change whatsoever physically and energetically? If not, what could it be?