
I don't and never have gone for scans. For me, if I get a couple of good matings, I wait. Scans will only confirm, or not, a pregnancy at the time of the scan. There are no guarantees that the pregnancy will carry to term. Further, when a bitch is pregnant, she should be leading a stress free life, and as going to the vet can be very stressful for some dogs, I'd not put mine through that. Or for that matter, risk infection - sick dogs go to vets after all!!
If, by the end of the pregnancy, no puppies appear within 2 days over the due date, then I take mine to the vet for x-ray which is far more accurate in any case.
Scanning only really lines the pockets of vets. So unless there's a need to know at an early stage (mistake mating?) so decisions can be made, I'm against all this scanning. My opinion.