so I have had a sexual partner but I knew them and it didn't seem likely they had any stds, about 1 month later i got symptoms such as pain in the rectum, pain when ejaculating, consistent pain in urethra and pain in my testicles.I got a checkup and the doctor found traces of blood in my urine, which could be caused by erosion in the urethra bc of infection so i was prescribed 1000mg of azithromicyn and doxicycline( 2 pills a day for 3 weeks) I told my partner at the time to get tested and she came back negative, so what could I have?