
With my breed, and it is relevant, I'd never let them go to 66 days from the first mating without at the very least, having my vet take a look. Two days over and it's off to my vet. Mine tended to go into secondary inertia - start and then not progress. And for every day they just 'sit', growing, the more likely the need for a C.Section. With a small litter they can 'sit' too.
I didn't set much score by temperature taking.