Tissue and blood in urine - is this a UTI or something else?

Hi. Im hoping someone can help me out with what ive been experiencing. About amonth ago, i woke with strong UTI feelings - urgency, pain, and pain in my lower abdomen. I also noticed blood and then i realized that i had been having pinkish urine for about a week or two prior to the onset of the UTI feelings. I started with herbals with my OMD (im a lay herbalist and dont use antibiotics or drs unless absolutely necessary) - UTIS are often easily treatable with herbs. They relieved a lot and then i noticed it still seemed to linger and would come back if i didnt flood myself with water. Waking up 2x to urinate at night and in morning dark yellow urine. I went to the doctor yesterday, as 4 weeks and a vareity of different herbals havent kicked it out yet..........in an in office dipstick test they found no bacteria, but blood........so they are doing a culture, which i havec yet to get the results back from. I noticed yesterday what looked like pieces of tissue in my urine. This is not from vagina, but absolutely from urine. They are smallish, some maybe about 1/4 inch long and slightly stringy witha bunch of small specks. They are white colored. I have been having this for a few days, but hadnt looked at urine in a clear glass to see how much this was. I did research last night and all i can find is renal necrosis. Im only having some low abdomen pain occasinoally, and increased frequencey of urine. It almost feels like my bladder wont hold a lot of urine nbefore i get the urgency feelings. I am wondering if this is a lingering UTI or if it is something else. I have called back the dr to tell them about tissue findings and am waiting to hear back. Im thinking the tissue from renal necrosis would not be white, but cant find this info anywhere to confirm or deny this. I woudl also think i would be feeling pretty sick or at least have bad back pain........ I have no back pain, no fever - just the lingering uti stuff and blood in urine (not really visable anymore). Could this tissue also be mucus? and is mucus present with a UTI like this? As you can tell, im fairly woriried. I know i have to wait a few days for the culture to come back, but these latest findings have me unsettled. Any thoughts or comments are very much appreciated. Thanks much