Hi Tyson,
I would'nt worry about it too much, most likely all pups were dead at the time of birth, this is often the case when prematures are born at the same time. Wether the prematures are the cause of death, or the death of a big pup causes the mother too get rid of everything is unclear.
Better luck next time.
By the way another option is too separate this female in two months time so that there is less chance of complications next time.
Greetings Mark