Flying 24/25 weeks pregnant

I’ll be flying at 24 and 25 weeks pregnant on American Airlines. The only thing I can find online directly on their website is :

“For domestic flights under 5 hours, you won’t be permitted to travel within 7 days (before and after) your delivery date. If you need to travel within this time frame:

Approval from your physician and a special assistance coordinator is required.

Your physician will be required to fill out a passenger medical form before your flight. A special assistance coordinator will send the form directly to your physician”

So how would I prove I’m only 24-25 weeks? Do I still need a note in case they ask me? Do you know what the note needs to say?