I masturbate fairly frequently – maybe 4-6 times a week – and I find that sometimes when I don't masturbate, I have a "wet dream" at night. This is annoying since I have to get up in the middle of the night and change. Has my body gotten so used to ejaculating that if I don't make myself ejaculate, my body will do it for me?
This is uncommon – most people who masturbate with anything like your regularity rarely (if ever) have nocturnal emissions. Still, that doesn't mean there's anything wrong with you; your body probably just has an unusual need to release semen frequently. Still, as always, if anything seriously concerns you about your body, it's wise to discuss it with a doctor.