> Do I just wait until day 63 and if she is showing no signs ask my vet to do a cesarean?,
Depends on breed and size of the bitch. My breed don't go 63 days, so waiting to see a vet on day 63 would not enter my head. I have to say that I am probably in the minority. I have had plenty of singletons with no problems, and have not found them too huge for a natural birth. This in a breed well known for difficult whelping. Consequently whether it is a multiple birth or singleton is irrelevent to me.
You definitely acquire a gut sense for inertia. Some people just don't recognise it, and the bitch suffers. There are no contractions, but the bitch is in pain. She can't tell you, and you need to be attuned to your bitch. Look for the pain and distress in her eyes. It's the only way you can tell. For a vet to say that labour should start on its own, really shows you that vets are not breeders.
Personally, if a bitch needs a section, or needs oxytocin due to inertia, I never breed from her again. (She is spayed, and kept as an auntie!) :-)