Babies in the womb sleep 12-14 hours. Maybe he was just sleeping. Kind of rub your belly and jiggle it a little bit(not too rough) to wake him up for a few minutes. but I'm sure he's perfectly fine. My baby didn't move during my baby shower either. I guess cause he was either sleeping or didn't recognize any people's voices.
Call your doctor / Ob/ midwife and talk to them.. you should be feeling him move 8-10times every 2 hrs.. lay down on your back DRI k water or juice and count how many time he moves