Based on my one and only time dealing with this, I would agree completely with the above statement. Chloe nested for about 2 days, but when she looked almost frantic - I knew that it was very close.
As I was told by many of the breeders on here, it is important to pay attention to the part when she begins to push. More specifically, you want to make sure that she isnt pushing and straining for more than an hour - two hours (depending on who you ask). You will see her neck stretch and if you look, you can tell that there are some contractions/pushing going on.
Good luck! Sending a prayer your way.