It varies from dog to dog depends a lot on how settled she is. A dog can delay their labor simply because they don't feel safe where they are at. When their temperature drops labor should start within 24hrs max. If she is not starting to push the first pup out despite her temperature having dropped and her having been nesting, panting and dilating, then it's time to call the vet. She should start pushing within 24hrs after temperature drop. Once she starts pushing the first pup should be delivered within about 1hr. If the first pup is not fully delivered within 2 hrs, call the vet. In between pups a bitch can rest for up to 4 hrs. If she waits longer than that, call the vet. You should've had x-ray or ultrasound done about a week ago so that you would have an approximate number of pups that you were prepared to deliver.
