I am a very responsible dog owner. My minis. Are my babies and frequent the vet to ensure their health. I know that an ultrasound at 30 days would confirm pregnancy was wandering earlier signs to more comfort my pet.

You breed your dog (obviously)?

Call your Vet. Dog Pregnancy Timeline | Signs Of Pregnancy In Dogs | How Long Are Dogs Pregnant

Weight gain and a change in behavior are probably the most obvious signs however they can also be signs of a phantom (false) pregnancy. Really the only surefire way to tell is with an ultrasound as you said. Ultrasounds are good for determining the rough size of a litter, they are not 100% accurate in determining size though as pups can often hide behind each other but it will give you a general idea of what to expect.