You have not mentioned breed of your dog. Dogs can have one puppy in the litter and this is normal. When labor starts, dogs start to shake due to pain and strain in order to push the puppy. After delivery of first puppy, dogs can take rest for maximum 2 hours with an average of 30 minutes before giving birth to to second puppy. After resting period, dogs start to shake and strain again for the delivery and this process continues until all litter is born.
If dogs continue to shake and strain without any delivery then it means she is having another puppy and delivery has become difficult. This condition requires vet help immediately. If dogs don't strain even after 2 hours then no puppy is left inside. So, In my opinion, your dog has delivered complete litter that has only one puppy and is normal.
If dogs continue to shake and strain without any delivery then it means she is having another puppy and delivery has become difficult. This condition requires vet help immediately. If dogs don't strain even after 2 hours then no puppy is left inside. So, In my opinion, your dog has delivered complete litter that has only one puppy and is normal.