Had a kidney u/s for rt flank pain was neg a month ago. now i have microscopic hematuria, going to see a urologist. chances of bladder tumor?

Microhematuria: I can't give you chances, but I can tell you that one of the reasons for Microhematuria is bladder cancer. But infection is also a reason, stones in the urinary system are a reason (they may not be seen on ultrasound), and there are other reasons. So rather than worry yourself sick, eat a few of those great walnuts grown around there, and wait and see what is going on.