I'd have to agree with FD. My grandfather had this same problem for quite a while and it was both his prostate and his bladder. I'm not going to tell you what he had because it's a worse case scenario and it's not worth worrying you over.
Hematuria (blood in urine) is nothing to play around with, though. You seriously need to talk to your doctors about it and see what they can do. It could be as little as something like a UTI or as serious as bladder cancer.
If you have had no pain with your urination, though...you probably shouldn't have too much to worry about. Hope I helped you out some.
Good luck!