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I would say she has delivered them late and they have been born dead She will have disposed of the dead pups in a natural way. It's normal to see blood around the underside after she has given birth but she should clean it up over a few days and return to normal. If she doesn't and shows signs of continuing discharge she may have an infection and would need to see a vet urgently.
They can take a few days to recover though and sometime have an upset tummy from disposing of pups.