Well, to ease your mind, I thought I would tell you my experience.
About Day 18, I think I peed a tumor. First I peed blood and then the urine turned dark and brown. About the third time, I peed into a white cup and it looked like black strong coffee with cream. I slowly poured the cup out and in the bottom was some very black gummy looking stuff. A couple days later the urine cleared up which made me very happy although I was never worried about it at all because I think I was hoping for something like that.