A dog pregnancy lasts nine weeks, calculated from the last mating. The pregnant female will deliver 59 to 63 days after conception. If she has bleeding or discharge before the end of her pregnancy, take her to the vet to ensure she isn't losing her litter or suffering from an infection.
Most dogs have no physical changes before five weeks of gestation, though some display signs of "morning sickness" around three weeks along.
Her nutritional needs change as her pregnancy progresses, and she will be eating about double her usual serving by the eighth week of pregnancy.
Your pregnant dog needs to maintain a regular exercise routine to keep her in good shape, which makes for an easier delivery.
Monitor her carefully during delivery to prevent her from having pregnancy complications that escalate. Some dogs prefer to whelp in private, but check periodically.
It is a myth that the dog's temperature drops within 24 hours of labor. A change in temperature is just one of the signs that labor is beginning, not the primary one.