Get Your Dog Care Questions Answered by Experts
Are you sure that you have the dates right? It certainly sounds like she is in labor.
If a dog miscarries, you usually don't see any signs of it.
I suggest that you see the vet first thing tomorrow so that they can x-ray or ultrasound to see how old the puppies truly are.
If the puppy(ies) have died, you need to find that out as well.
Let me know if you still have questions.