So I had 2 females that were pregnant days apart the first one went passed her due date been checking daily.. the second one had hers today healthy litter. Went to check on the first one and still no babies in the nests I found one on the floor severely deformed was no back legs looked like 2 was blended together no other babies .. and no she is not related to the father in any way and she has had litters before.. so not first litter. What happened and how do I prevent . And is she ok?