There are many reasons why your dog could have stomach swelling. Your dog could have a twisted stomach for example.
call the vet
When it get swollen it might be that she is pregnet
Somewhere on the stomach because when they spay a dog they take out the uterus and overies.
I can't think of what it is called but its when the stomach does a turn and food cannot get in or out of stomach,its serious, call your vet ASAP
Because she has just undergone major surgery and anybody would be a bit swollen. If it lasts more than a couple days you should ask a vet.
Your gonna have to feed the pups yourself if you don't your pups will die. If the dogs breast are swollen then your dog is sick.
The teats should not be swelling at all after being spayed unless they were swollen before the surgery. You need to take your dog in to be checked out by your Veterinarian as soon as possible.
when the stomach looks swollen or a little red and a little fat
I had a dog who went through this, it was an accumulation of fluids. The surgery was properly poorly done, take her to the vet, she might have an infection as well.
I suggest that your dog has been spayed. If your dog has been spayed she will not go into heat.
Spaying is the removal of the ovaries from a female dog. No dog that is spayed can have puppies. No female dog can have puppies with another female dog. If you are asking about a male dog, the correct term is neutered, not spayed.
As long as the dog passes a veterinary exam, there's nothing wrong with adopting a dog that was being used for breeding. You should of course, have her spayed.