Protip:
Men, and other people with prostates, if you are pissing a lot of fresh, red blood, especially shortly after ejaculating, it's entirely possible that you have broken some blood vessels around your prostate. You should avoid ejaculating for a week or two (no edging, either, ya freak). If you do not do this, you may later discover that you have blood in your semen, too. Now you may also have a prostate infection, but don't worry, a course of antibiotics can handle that. Another symptom may be strongly feeling like you have to urinate when you do not, to the point of being debilitating.
However, if this happens to you, you must to go see a urologist to rule out bladder cancer. The procedure to rule this out is unpleasant, and involves sending a camera into your bladder, via exactly the route you think it does. You will be awake for this procedure, the anaesthetic gel is not very effective, and the camera is at the end of a somewhat flexible tool about the girth of a pen.