I figured you did but better safe than sorry (which is why I mentioned it - just in case).
A friend of mine had that problem with one of her girls, who happens to be my pups mom (not the litter she came from). After one successful delivery, the 2nd (and final) one needed a c/s. It was scary and stupid expensive because OF COURSE it was after hours at the ER vet. Ugh. 3 of the 4 made it. One of which she kept, a male, who she is showing. He visits us sometimes. Violet's annoying "baby" brother (he's 10 lbs bigger than her!)

And if you want to see something REALLY neat (I think it's neat anyway...)
When Nutmeg (the mama in question) was pregnant with that litter, we snuck her into my work and I did an ultrasound on her... :)
Sorry, not trying to completely steal your thunder... PUPPIES!!! I love puppies.