I flew at 26 weeks, pregnant with twins (30 weeks with my singleton, also last flight). Luckily I was in business, both were transatlantic, but I was flying by myself with a toddler. It was the last flight I made. I wasn't really into flying anywhere. Also you have to realize (and make sure you're medically / financially covered) that you could be going into preterm labor while at your destination, and you may get stuck there for quite some time. It depends on your pregnancy, previous pregnancies, but there are no guarantees. So take it into consideration, and think about the care at your destination, and if that meets your requirements.