Labor, Delivery, and Postpartum Care in Bitches and Queens
Stage I labor in bitches and queens normally lasts 12-24 hours, during which time myometrial uterine contractions increase in frequency and strength, and the cervix dilates. No abdominal efforts (visible contractions) are evident during stage I labor . Female dogs and cats may exhibit changes in disposition and behavior during stage I labor , becoming reclusive, restless, and nesting ...
Increased whining and restlessness are common signs of labor . It's important to monitor for additional labor signs like nesting or contractions. Consult a vet to ensure your dog's health and the safety of her puppies.

Why Is My Pregnant Dog Whining
A pregnant dog whining is one of the first signs of labor . Whining is a natural response to the pain of contractions. Look for other signs of labor , such as nesting, vomiting, and either pulling away from you or getting close to you. When a pregnant dog is whining and has been pregnant for two months, she is most likely experiencing contractions.

My pregnant dog is panting, shaking, whining. Is she in labor
Is your pregnant dog panting, shaking, and whining for hours without puppies? A certified vet explains these labor signs, potential pain, and when to seek immediate care for your pet.
This article explains the three stages of a dog's labor , from early labor symptoms (panting, nesting) to the actual birthing process to afterbirth.