A number of non-infectious causes can result in diarrhea. These include lactose intolerance, irritable bowel syndrome, non-celiac gluten sensitivity, celiac disease, inflammatory bowel disease, hyperthyroidism, and a number of medications. In most cases, stool cultures to confirm the exact cause are not required.
Most dogs are first bred between the 10th and 14th day after the onset of proestrus. As long as the bitch will accept the male, mating every other day for a total of two or three matings is generally considered sufficient. However, signs of proestrus are not obvious in some bitches.
Which means that a female could get bred to a male and not get pregnant until 4 or 5 days after the breeding. If you ask a vet they will refer to their text books and tell you that the time can vary from 58 to 70 days after a breeding before a female whelps her litter.