
Yes, bitch appeared to be in whelp at 5 weeks, (she had already had a litter) but then within a few days seemed to go flat, and of course no pups.
I had not had her scanned though, but bitches can resorb up to about 6 weeks, until the bones start to calcify.
I also had a litter with 2 mumified pups, who had obviously failed to be absorbed.
It was always suspected that tesorbtion happened, and the advent of scanning has confirmed that it happens quite often.