M.M.
I have had benign microscopic hematuria for 20+ years. I was diagnosed in my early 20's. I've had every test under the sun (several tests have been done multiple times) and they have found nothing. Some people have this condition lifelong without any problems. I don't have an problems with recurring UTIs, pain, etc. My condition is monitored by my PCP and urologist on a regular basis.
Have they done a urine cytolgoy culture checking for malignancies? They will most likely do a cysto which now can be done in the office rather than an outpatient procedure. A small scope is inserted to look at the bladder and urethra. The test is mildly uncomfortable but nothing horrible. I was able to get up and drive myself home without incident. Other tests could include IVP (intravenous pyelogram) and renal ultrasound.
Hematuria can mean a million things and most causes are not anything to worry about. You are very smart to follow up on this. You can't change it so try to relax and not think the worst (easier said than done, I know).