I think Parker missed that you are the Canadian citizen... so, no medical needed for you, and you can apply for citizenship for your baby, so they won't need to be included in the application. (but you may need to inform CIC about a change in your husband's family composition if babe arrives before he lands)
And, as a citizen you can move back to Canada anytime you want...your husband cannot "move" with you, but he can "visit" you so you can be together while he waits for his PR. However, he cannot work until he gets his PR, as you will apply Outland, which you would need to do if you are both living outside Canada (Canadian citizens who live in Canada have an option to apply Inland, and then it's possible to work after about 6 months).