What are signs that my dog is in labor?

Typically the first sign is they'll lay down but seem uncomfortable.

after a pregnancy length of about 63 days, your dog will begin to show signs of labor. She will exhibit several precursory signs prior to her actual labor, and then she will likely have a drop in body temperature, followed by physical labor

Watch your dog for restless, nesting behavior. Give her a bed in a quiet area with enough bedding to make a nest. Towels, small blankets and newspaper can be good materials for her nesting bed. Your dog may scratch around energetically in her bedding one to seven days before labor actually begins.

Pay attention to physical changes taking place in your dog's body. As labor time approaches, your dog's mammary glands will begin to enlarge; milk may be present two to nine days before she gives birth. The vulva may become swollen, and a clear to slightly cloudy discharge may occur.

Take your dog's rectal temperature twice a day. If you have never taken your dog's temperature, consult your veterinarian for the proper procedure. Normally, a dog's temperature is between 100.5 degrees and 102 degrees Fahrenheit. Approximately 24 hours before labor, your dog's temperature will drop below 100 degrees.

Examine your dog's abdomen. As labor approaches, small contractions will cause the abdomen to harden periodically. The frequency and intensity of the contractions will increase as labor become imminent. Her abdomen will feel like a bag of rocks, and her appetite may dwindle.