Did you not read the
www.debbiejensen.com site that was posted to you before on another thread so you would know what you should be doing now?
I would get a call in to your vet NOW and hope that maybe the due date was miscalculated. It sounds very much like she is in labor whether the pups are ready or not. You have posted that she is about double in weight with this pregnancy and it's likely that her system cannot take the strain. Whelping a tiny would be no picnic for even an experienced breeder and you need to get some hands on help now or risk losing her.