most dogs will wander... but eventually will come back.

I lost my dog for a day once (Panamanian black lab mutt) but it wandered back at 2AM the next night.

Do the obvious and post lost posters in a couple mile radius, check animal shelters, etc. someone probably found it and either called the pound or is keeping it at their house (and hopefully) putting up found posters.

I know how it feels to lost a dog, good luck on getting it back.