If you don't hear it drop or see it drop, sit still and watch.
Everything eats deer, so they run. If there is not huge trauma, like breaking their leg ( another good point about a sharp broadhead) the deer will likely run to the first available cover, stop and stand there, watching to see if what ever it was is following them.
If you sat still, didn't scream " yeah I put the smackdown on that sucker" and dance in the tree for all ( including that deer) to see, then it will likely bed near where it stopped, still watching. It just got a sharp pointy thing run thru it and although there is very little pain from that, it is bleeding heavily.
Wait for a minimum time ( your time) unless you are worried about a too far back hit. Then sneak out of the woods and come back in the morning. It will likely be very near that initial bed.
If you hit it in the muscle ( butt, high leg, maybe neck) another tack is to get on the trail pretty quickly and keep it moving and bleeding freely. I have tracked deer that way and was successful, but it was a hell of a track and covered a bunch of property.
Just my thoughts
CHuckC