traveling internationally

Mrs.
Have any of you traveled internationally while pregnant? We have a Europe trip booked (I was pregnant when we booked but I didn't know at the time). I will be 20 weeks during travel but the flight will be around 10 hours nonstop. I am concerned my legs/feet will start to feel numb but this is my first pregnancy so I have no experience. Any advise on how to stay comfortable for that long of a flight?