Blood in semen for several months??

Hello, I am a healthy 30 yr old that first experienced blood in my semen and urine about 5 months ago during a long raod trip to mountain bike and visit my girlfriend.  I initially thought that there was bike-related trauma but the bloody semen continued so I went to the doctor and eventually to a urologist. He did MRI on bladder and kidneys with tracer tests, blood tests, and eventually a cystoscopy. Everything was normal except my prostate was 'larger than a normal man my age' but apparently not alarmingly so, and there was some 'cloudiness' in my bladder which seemed to perplex him and he suggested that I try to empty my bladder, which I have always done anyway. The doctor did not do anything about the blood in my semen and didn't even mention it after the initial visit. However, the bloody semen continues and has me worried. I also feel like I urinate more frequently that I should and that the urge to urinate comes on urgently. There is no obvious blood in my urine. Should I seek a second opinion? Thanks for any advice - I just want to know what is going on and how I can address this troubling issue.