I think my dog has run away?

Well sadly in this kind of situation all you can really do is pray there alright!! :'( I would go and search around your neighborhood to see if he is around there somewhere, most dogs don't tend to stray that far from there homes. Also if you normally walk your dog around a constant route, I would check that as well, my fox terrier got out once, and he came back an hour later from the same route I usually take to walk him!! :) If he got picked up by animal control they'll call you and tell you they have your dog, if he is still not home and you haven't gotten any information about him after three days I would put uposters around your neighborhood. I'm sooo sorry for your bad luck!! :'( I hope you find your dog soon, safe and unharmed!! :'(