It's not too early to be prepared and know all you options...just make sure you don't cross the line between "preparing" and "panicking." Hard to do, I know.
It is too early to tell for sure if she is preggers or not. Any 'signs' she is giving you now, like the ones mentioned in the previous post, might give you an indication, but you have to remember also that the same 'signs' may be there for a false pregnancy. So in short, you can't reallyl rely completely on them. Are you planning on having and xray done around day 50? That will probably be when you can tell "for sure" if she is expecting or not and will give both you and your vet a heads up if any of the pups seem to be to large for her to deliver naturally.
Just try to stay calm and wait it out. If she's preggers, then those pups will be here soon enough.
