Myoglobinuria following myomectomy

[Clastegra]

I had a myomectomy a year ago and continue to have adhesion pain sometimes to the point I can hardly walk ( mainly if I've been on my feet too long and really overdoing things ).
A recent urine dipstick showed +++ blood but lab results come back as normal so I'm wondering if it could be myoglobinuria.

Ultrasound of kidneys and cystoscopy of bladder found nothing ( I was concerned about urology cancer )
So now I'm left with blood on dipstick n nothing else.
Please help if you can x

I am not a medic but wonder why you would suspect that if your urological investigations have come back clear?

Tests have come back clear for tumors , stones etc but still showing blood on dipstick so must be some reason for it.
Myoglobinuria will show on dipstick but not on lab MC&s in lab so wondered if my muscle pain from previous op could be causing it or possibly my very low iron count.