Re: Broken rib in late pregnancy = c-section?
I would contact the MW/doctor who will be taking care of you for the final decision. ER Docs are great people who have a large breadth of knowledge but not a huge depth of knowledge in all fields. I would have a long conversation with your personal doctor who's going to be doing the delivery with you about it...someone who's specialty is birth. FWIW, I know several people who've broken ribs and haven't had c-sections so I know it's not a definite thing.
hope you feel better.