Hi my bitch is 6 years old, she has had one previous litter, (which all went well, born on day 63).
Since 5am Friday morning she has been going through stage 1, panting,restless, nesting, with short periods of sleep. The pups are still kicking, but due to her age should I just monitor her for as long as it takes or after 24 hours (so 5am Sat), should I call vets? She’s currently napping. I had her checked on day 65 of pregnancy and today is day 67. I am only concerned because vet mentioned a condition where sometimes in older bitches the uterus doesn’t contract. How will I know if this is a problem. She has had no discharge and had not been straining. Sorry if it seems a silly question, I’ve been sleeping with her since day 63, just in case, so I guess I’m a bit tired and worried right now.

Did you have one mating or more as this can make a difference to the day she conceived...it may not be as far on.
It would concern me a lot if today is day 67 from a single mating, especially as some breeds are known to be early whelpers...

She only had the one tie. I took her to vets on day 65. They said to allow at least two more days but up to 5! Spoke to them this morning again and although she was restless at 5am she was ok until about lunchtime, when the nesting snd osntingvreally started, so allowing 24 hours from then. They said not to worry as no discharge and pups kicking. I’ll call them again later to update them. She seems comfortable just tired.

FWIW I've never allowed any of mine to go over by more than 2 days from the first mating.  That is if by day 64 nothing was happening, I'd involve my vet.   And immediately before whelping, our puppies usually went quiet - I assume getting in line to be born.   She may be fine but after the due date, with puppies just sitting, they are growing bigger by the day making the need for a C.Section more likely.

Unless you know when ovulation was, it's very hard to predict whelping. 

Eggs typically take 48hrs after ovulation, to be fertilisable and semen can live up to around 5 days on average from a fertile dog.  It can be longer - up to 7 days.

So you could count up to at least 5 days after the mating, for conception to have happened... maybe longer.

You definitely don't want to do a c-section if you're too early because the pups may well not be viable...

I don't think any of my vets would do a C.Section until they gave a shot (maybe two) of oxytocin first and nothing happened.  That should avoid premature 'Sectioned puppies.  Mine went into secondary inertia more often than not which is why I didn't leave it more than 2 days over.....  each to their own experience!

Just spoke to vet again he said it’s not unheard of for dog to go 72! And as for 1st stage usually no more than 24 but can go up to 30 hours! He said to leave it until 3pm.

Any vet who says a bitch can whelp at 72 days is a vet to be ignored. Few vets know anything about breeding and this one clearly doesn't.

You definitely don't want to do a c-section if you're too early because the pups may well not be viable...

Even if the eggs weren't fertilised until 5 days later this bitch would still be on day 62 at least, by which time my bitches will usually have whelped. I had a litter of 4 once born on day 55 -toy breed- (just -it was after midnight but not morning so almost day 54) and those pups were all good sizes and all survived and are now 3 years old. I always count  day 55 as first possible day for my toys now and day 57 for my large breed.

Yes, I didn't have time to do the math :)

I would have changed my vet by now.  And having great worries over a bitch this age.  Please come back and tell us if she is ok.  I am so worried for her.

My beautiful clever girl knew her stuff as did the vet, can’t praise them enough for their encouragement and for contacting me constantly for updates. Thank you Oliver from The George!!
Maisy gave birth naturally to six very healthy beautiful pups, all a good size and very active. Mum and pups (4 boys 3 golds, 1 lemon white, and two girls, one Tri and one black with white blaze), are doing great.

Excellent news! Bitches never read the books and generally know better than we do.