A miniature pinscher has the same gestational cycle of all canines, which is between 64 and 66 days. A veterinarian can diagnose a pregnancy as early as 16 days into the pregnancy.
A dog may not show pregnancy symptoms until the end of the second trimester, around 40 days into the gestational cycle. At this time, the stomach begins to get larger and the nipples become larger and redder. At approximately 45 days into the pregnancy, a vet can take X-rays to determine how many puppies can be expected when the mother goes into labor. The process of giving birth is called whelping.