International airlines will not let you fly after 33 weeks on an international flight...you can fly later domestically but not international......the only way they would let you fly on a long haul flight after 33 weeks if there was an exceptional circumstance like someone in the family died AND you could prove you were fit to fly...that would mean absolutely zero pregnancy issues, no swelling even etc...they are very very strict on long haul flight issues as if something happens they can't exactly land the plane in the middle of the ocean!

So you will need to rethink how much time you take off work both before and after to allow for this....