Breeding a dog and still a false pregnancy!?!?

Question
This is my dogs 3rd breeding. Its been almost 2yrs. since the last(so I don't remember when I bred my female the days of her cycle)breeding/litter. The vet palpitated her and said there is 1 or no pups! Yet my female acts like she did when she was pregnant the last time. She digs/nests, has 1 teat that has a milk and a cloudy brown liquid in it, shes big but not huge and eats more. I really want to know if she didn't take or she did and something could of happened? Like some sort of miscarriage or she is pregnant and is hiding a pup or two? Also, is it true that the uterine wall could be swelling and that maybe the reason why no one can feel puppies? I'm concerned this is her last breeding and she will be fixed with or without pups. Please! Help me if you can!!!

Answer
Hi Kris,

During a false pregnancy a female will get bigger, get milk and start nesting. A false pregnancy is caused by a drop in progesterone levels much like when whelping begins.  It's very common in dogs.  

The only way to see if she is in fact, "hiding a pup" is to do an x-ray.  That way you can put your mind at ease.

Good luck.