i flew with emirates at 30 and then returned at 35 weeks. you will need a certificate from your care provider as they can refuse you (they can claim that you might be lying about your dates etc). so even if you are only 27 weeks, i would have one under your arm JIC.

also a really good idea to know what the cut-off dates are for the company you are flying with. when i checked in with Emirates the lady wanted to refuse me boarding saying they dont fly with women that prg...i was able to shut her down with a print out of their policy...

buy compression stockings too!

have fun!