I've had blood in my semen at the end of my orgasms (when using the muscle that makes the penis have a throb or pumping action) I use cock rings frequintly and have masterbated with them on for several hours at a time! Sometimes under the influance of methanphetimes.I've seen this happen before and was told that I had a trauma to the scrotem area and ceased any activty there for a few days! And then did not have problem again until about 2 weeks ago.I tried the same remidy and still have blood at the end of the orgasm.it has happened about 3 or 4 times now.I dont have any blood when I urineate or any other time.So my question is should I just stop any activity for a longer period or could I have permenatly damaged something and need to see a doctor?