Perfect. Thanks for the additional information Joel. I really appreciate it.
Even though your vet didn't mention if she was in heat when she was spayed, I suspect she was just on the tail end of it...especially if she had been in heat in September (the heat cycle actually lasts 21-25 days). Because of this, I suspect she's got a false or phantom pregnancy going on.
Pseudocyesis (false pregnancy) often occurs when a dog has been bred but doesn't get pregnant or is spayed while still in a hormonal peak after a recent heat cycle. You can find more information about this here:
Unfortunately, there isn't anything you can do to get a dog to stop a dog from acting like this during a false pregnancy. They have this issue strictly due to hormonal imbalance and the body thinking that there are puppies to nurse. This issue will usually clear up on it's own after a few weeks.
If it doesn't, or if you notice any swelling to the mammary chains, lethargy, anorexia, vomiting or diarrhea or heat to the touch on the mammary chains, these are all signs of an infection that needs to be looked at by a vet as soon as possible.
I hope this helps.