I should add, this isn't my litter... But we're hoping for a puppy from it.  A very experienced breeder who must know what she's doing, too.

Today (Sunday) is day 64...

Entirely breed related. If it was my toybreed, by day 64 pups would already be dead. I'd not go past 60 days there. If it was my large breed, I'd go to day 65 and not a moment longer but would seriously start to worry by day 63.

Thanks, it's a large gundog breed.

I had a healthy litter born naturally on day 68 - the vet was ready to step in at a moment's notice. She was late ovulating that season too - we didn't mate till days 18 & 20.

Thanks... Been waiting since last Weds...!!  Very stressful, all this waiting!

Just to let you know, things are kicking off now - phew...

With mine, I'd not react until my bitch is 2 days over the normal 62/63 days.   Unless she's unduly restless, has a nasty discharge etc.etc.