Good for you, SM!
Fawndallas, there is really NO way of knowing what's going on in there without a trip to the vet. However, since she hasn't passed her first due date yet, that gives you a little leeway, though not all dogs go 63 day with a pregnancy.
I would maybe give her a little more time and see what happens. Like I said, once that mucus plug goes, the pups can't be too far behind! One tip I was given to help stimulate labour was to get the bitch up and walking, but this was for a female that was definitely in full-blown labour, and had already birthed a couple of puppies. It did work, though. We even ran her up and down some stairs to help thing along!
I've helped with the delivery of 2 litters, and am a registered nurse, so I have good medical knowledge. Let's see what the more experienced people on the board have to say.