I just whelped a litter last Friday. This was her first litter at almost 3 years old. #1 was born at 10 am, almost 3 hours later #2, an hour between the next 6 and 4 hours between #8 and #9 the last one. I called the vet mid day and he said some females that are super calm and relaxed just take their time and not to worry, if she passed something other than normal birthing fluids and placentas and pups, call immediately. But all was fine. I thought #8 was it, cause she was acting normal, wanted to go outside and out plopped #9 in the snow, she flipped around and was just as shocked as me! We lost one pup yesterday, he was the first born and the smallest, he didnt' seem to want to keep up, even with me supplementing.
I had litters last year that had 5 pups and 8 pups and they were done delivering in less than 4 hours the whole litter. and my litter on Friday was oer 12 hours. So I guess it depends on the female.
I also heard giving them raspberry tea helps them relax and speed up delivery and I would have swore by it until this litter.
Good luck and I hope you will share pics too
Kari in Montana