One cool tool for early confirmation of pregnancy is Ultrasound.  You need some pretty specialized equipment, so not every veterinarian can do it.  We made an appointment with Dr. Baker at Wadleigh Falls Veterinary Clinic in Lee, New Hampshire.  Dr. Baker was great to work with and we had fun at our visit.



First they wheeled in this machine which looks a lot like a computer on a cart.  I guess that's pretty much exactly what it is, except instead of a flat bed scanner, it has an ultrasound scanner.



We gently restrained Iris on her back and Dr. Baker prepped her with some simple rubbing alcohol.  Then it was a simple reading with the wand.  I'm certain he made it look simpler than it was, but it Iris was in no discomfort at any time.



We got to look at the images on the screen, and then Dr. Baker printed some out for us.  Here is the clearest one (a photo of a piece of paper).  Can you spot the spine and head?



I think you need some image of your pups prior to whelping.  If you know about how many to expect, you are better prepared if say three come out and labor stops.  If you are expecting three, cool.  If you are expecting five, you have a problem.  If you don't know, you don't know if you have a problem or not.  Ultrasound is the tool that allows you the earliest count.  I still prefer an x-ray a couple days prior to your whelp date, but if you like an early answer, this is a powerful tool.