It's heading toward 63 days after your dog was bred -- the average canine gestation time -- and you're looking for signs of the impending birth. If you see her pass mucus, she should enter the active stage of labor within 6 to 12 hours. Since this sign is easily missed, there are better ways to predict her whelping.
Canine Whelping Signs
Within the 24 hours before labor begins, the mucus plug that covers and protects the cervical canal releases. The American Kennel Club website warns that the mucus release isn't very noticeable. More reliable indicators include restlessness and neediness in the expectant mother. The AKC advises taking the dog's temperature twice daily, morning and evening, starting a few days before the due date. Normal canine temperature ranges between 100 to 102 degrees Fahrenheit. Once the dog's temperature drops by 1 or 2 degrees, she should go into labor within 24 to 48 hours.