Painful semen discharge at night

I am 18 years old and I have notice painful semen discharge 2-3 times caught on underwear during night.Semen was white colour.Last one was about 1-2 months before. I don't feel any pain while normal ejaculation & also semen smell in urine sometimes.What could be this?

I think the only medical professional that can help you with these issues is a Urologist. Particularly the semen smell in your urine.