Me and my friends made a minecraft server, and we killed the dragon and got the egg. once we got back to our base, we put it on a pedestal, then one day I hit it with my hand when trying to do something and we can't find it at all, we've searched in about a 32*32 block radius, and still can't find it
"teleports to a place nearby (up to seven blocks vertically and fifteen blocks horizontally), creating the same particles as endermen. It may teleport into the air and subsequently fall to the ground since they forcefully obey gravity. "
assuming you accidentally hit the egg while in survival mode - if in creative .. then it's been destroyed
One thing you could try is installed one of those X-Ray mods & set it up to show only the dragon egg then use the mode to see if you can see it anywhere nearby