From my personal experience ,me and my wife had done much travel during her pregnancy ,for her and my job.
She came to US on her 30th week of pregnancy .
Check with your carrier ,what do they need on 30th week ,for eg :Medical certificate ,which is not more than 1 week old.I will suggest you to get this 2 to 3 days prior to the travel ,which is more safer to your wife as well, also in the carriers preffered format ,which you can find on their website.
My wife had administered ,precautionary medication ,to prevent any bleeding ,as she did some travel ,also the US journey is too long.
Make sure you are covered ,If you just moved to US ,it will take some time to start the insurance to start in ,this is called the waiting period.
You will have to find a doctor ,plan for this well advance ,if atleast you are there in the US prior to your wife.
The doctors may not be accepting new patients ,so you will have to find one who can accept you ,which will depend ,if your wife doesnt have any complication ,then this shouldnt be a big deal.
You can PM me if you want more information.