No flying 36wks+ and thats only with dr approval. Flying at high altitudes exposes you to higher levels of radiation. It will not rupture your water, thats been proven. Do some research too momma. Good to have knowledge :)
Depends on the airline. Some won't even let you fly after 24 weeks.
I flew really early. Around 10 weeks. Ascending and descending hurt really bad. I would suggest to avoid flying if possible. Not because it will hurt the baby, but because it hurts YOU lol. The pressure changes are no Bueno for your tummy which is already stretching. It was very painful.