Swollen Urethra

Dear Doctor,
I had bladder surger when I was a child. I was born with my ureters not firmly planted onto my bladder and thus suffered from reflux as a little girl. I had the surgery when I was three years old and have not suffered from Urinary Tract issues until the past 14 months.
For the last year I have had a series of what seemed and felt like bladder infections for which I have take antibiotics many times for. However whenever I have been to the Urologist's office and gave a urine sample, I never had any Nitrite in my urine. My leucocytes were high and I had microhematuria. I have had 4 ultrasounds done for my kidneys and bladder in the last year and they have been normal. I have also had two urethral and vaginal swabs in the last 6 months testing me for any sort of STD like Chlamydia or Gonorrhea as well as Candida and they have also turned up negative. Not to mention the two Pap Smears in the last year as well - all negative.
Last week when I felt like I was coming down with this again, I went to the urologist, had an ultrasound done and he said that my bladder was full. I had given a urine sample and emptied my bladder just 20 minutes before I had the ultrasound so I was surprised to hear that my bladder was full, but then again it's also not surprising since I had been drinking a lot of fluids that day as I felt like I was coming down with something. Anwyay the urologist said that if the bladder was infected that it would not be able to fill up completely as the bladder contracts much more often and is not able to fill itself up when it is infected. He did a cystoscopy and looked at my urethra. He said it was swollen and lightly infected, but that it was so light that he was not going to perscribe me any antibiotics. He said that I had Microhematuria and that I had a 'mechanical swelling' of the urethra. Since I had no bacteria or leucocytes in my ureine he sent me home with a perscription to drink a lot of bladder and kidney tea. Since then, 5 days ago, I still feel my urethra. Something does not feel right as when I urinate I have a very light burning and when I sit I feel a light pressure in my pelvic area. I know this was triggered by having sex with my husband, but we used a condom and I urinated and washed very very thouroughly immediately after intercourse. So I'm really confused as to what this could really be. I have read about urethral cancer, but I don't want to be a hypcochondriac and start thinking I have cancer, but after reading the symptoms of it, I'm thinking it may be a possibility even though my urologist did not suggest it as a possibility when he did the Cystoscopy a few days ago. Please advice on this.