Hi Lynn,
My gynae said I could travel till 36 week. But flight no moe than 5hours. I am 34weeks now.
I guess it all depends on how you feel & how your pregnancy is progressing.
If you are travelling alone, you'll need to prepare a list of emergency contact nos. And make sure all the service providers know you are pregnant, ie airline, hotel etc.
And you need letter from clinic saying you are fit to travel. Also depending on airline, some make you sign indemnity form.
ps. I stop travelling at 28wk...too much hassle, and my water retention getting bad...4hr flight was my max tolerance.