Suggest Treatment For Blood In Urine

Urinted steady stream of blood. No pain, no discomfort. Visited primary care doctor. Diagnosed bladder infection, Prescribed antibiotic with sulphur. Advised sonograms. Results indicate all ok but a "spot" was observed, not sure if clot or growth. Going to urologist in 10 days. What could the diagnosis of this possibility be? Am 78 yr male. No history of urologic problems. reasonably healthy but overweight.