I am 37 yr old male. Recently I ejaculated deep brown semen. Some times before after an excited intercourse, I found blood in semen. I see urologist and he gave tests starts from blood, urine, ultrasound, PSA etc. everything was OK except haemospermia with infection. The doc gave antibiotic. After finishing the course I found the sperm turned white again. After that incident, 9 months have passed already. After long paused intercourse (about 15 days) suddenly I found deep brown semen again. I am worried, can anybody suggest what has gone wrong?

There's really no way for anyone to give you a diagnosis over the internet.

Your only option is to go back to the doctor.