Hi Welcome to Healthcare magic....
Few more questions - 1)Do u have fever ? 2) Was there albumin
in the urine?
Presence of pus cells and rbc s in urine with a negative urine culture looks less likely to be a UTI , i would like to go ahead with another repeat urine culture and a blood culture
too in case you are not on any antibiotic.
Secondaly a urinary calculus(stone) can also present with such urinary findings.
Get a Ultrasound
abdomen looking for a urinary tract
Check your BP, with renal function tests to rule out glomerulonephritis
Anything causing bleed in to the urinary tract can have such finding .