This condition is known as retrograde ejaculation
. You should not have sperm in your urine unless it is immediately after ejaculation. There is treatment for this condition. It is also called that this problem can be a results of excessive masturbation
. I hope this helps. Get your self checked and let us know what you find out and how you are doing.
Do your urine RE/ME and culture if possilbe for further enquiry of your condition
Get well soon