Finding small amounts of sediment in urine, no blood/odor. Dipped myself which shows mod wbc. Horrible lower back pain (endometriosis). Any thoughts?

Could be UTI. I think it definitely could be a urinary tract infection but that should be checked out. Urinary sediment is certainly not normal which could signal other malfunctions going on and not just an infectious process. I recommend getting a urine sample looked at and possibly cultured, depending on what your doctor would like. Would get the sediment looked at microscopically.
See answer. In the absence of noticeable increased urinary frequency, urgency, burning, bladder pressure, a UTI is much less likely. Sediment in urine often related to the ph of urine, whereas the presence of wbcs in the voided urine of a female more often representative of vaginal contamination than infection. A urine culture would rule out uti. I suspect your lower back pain is not urinary tract related.