My partner is a pilot and we travel a lot. At about 11-13 weeks we spent 2 weeks in the states, came to Australia for 2 weeks around week 26-28 and had numerous other trips including one I just got home from yesterday at 35 + 5.

Unless you think you would find the trip very stressful under normal circumstances, then I'd say go for it. Most things like this are easier to do before the baby comes anyway and you don't now if you'll be able to get the opportunity again.