Check the membrane--if it looks dark brown moisten with coconut oil or olive oil. Work fast but carefully and toss in a couple of wet paper towels to get humidity up.One of my eggs has been zipped about an inch for the last 12ish hours. I can see it breathing but it hasn't moved. Do you think it will finish on its own?
Give it until morning and then help it out if it has not hatched.
Usually they hatch by then though