Hope that everything goes well because if it doesn't you have to go, lol. It's a part of making the decision to breed or even with an accident (which is also the decision by extension). We hemorrhage money pretty much when done even somewhat responsibly. We risk their lives any time we breed them. Read through the links I sent in the other answer so you can be a little more confident in what's going on, what to do and when you need to call your vet for help. That's only a phone call so they can get some more details and figure out what may be going on and whether to wait a little while or if your pup needs to go in. Some of those links actually contain a bunch of links so plenty of info there. Deep breath. They pick up on your stress levels. What kind of dog, how old, how big, how old the male, how big was he, is this her first litter, did you do the x-ray or ultrasound and confirm the pregnancy and whether or not it looked like there was going to be trouble?