GO TO DIFFERENT DOCTORS! My father had a similar, almost identical problem, and his doctor did some sort of special tests on him, and he had a milignant tumor on the bladder, and ended up being diagnosed with bladder and prostate cancers. Get it found and treated IMMEDIATELY... because of the length of time my father waited to get on the ball about the bloody urine, caused him to have his bladder removed.
Just keeping going back to the doc until they find something. Dont sleep on this one, it could be major.
Luckilly, my dad is now doing just fine, and living a relatively normal life.