my semen is dark reddish brown. i have been celibate for three years now and masturbate maybe every other month and that is when I see the dark semen. What can cause what appears to be blood in the semen. I just had a prostate exam and all was well. I didn t tell the doctor. I did have stress induced herpes about 4 years ago and was told to divorce my wife or die from the stress. I had the sore frozen off the tip of my penis & I m now divorced for almost 3 years.