
This sound very much like what happened to my girl with her last litter.. prolonged period where mucous plug was shedding, limited restlessness then waters coming away with no signs of pups appearing. I was advised to wait no longer than 2hrs which I did and then we went for a section. All 11 pups were ok but the first pup was very distressed and took a long time to get her to breath, it was touch and go for a little while and if we had left any longer and she would have died. Also the longer the cervix is open and there is inertia the greater the risk of post partum metritis as bacteria from vagina can track into uterus, normal birth flushes bugs out with pups. Another reason for not delaying too long.
IMHO you need to be off to the vet ASAP.
Out of interest progesterone test kits can be used to help with determination of need for C section :: Progesterone levels of 5ng/ml indicates whelping should occur within 24hrs. When progesterone level is lower than 2ng/ml this is an indicator for C Section. Ref :: C Dumont & A Fontbonne. Some in house Pre mate type Elisa test kits would give control ranges fror these levels.
Karen