I've been flying a lot over the past month, and still have a few more weeks of flying left (though I'll be done with travel by 32 weeks). Things I have learned?
- Get an aisle seat, preferably close to the back of the plane (for those frequent potty breaks!). Plus it helps with swelling to get up and move around a bit, so a restroom break mid-flight is perfect for this.
- Drink lots of water. While you can't bring a full water bottle through security, you can bring an empty one and just fill it up at a drinking fountain once you get through TSA screening.
- Wear comfy clothes, including comfy shoes. Slip on shoes are best, because you won't have to bend over and struggle when you go through security.
- Bring some of your own snack food. Airport food is expensive, and it's hard to find healthy choices (though they've gotten better and now at least carry fruit). Plus if you're stuck on the plane for a longer amount than anticipated, at least you won't starve (most airlines still give you snacks, but it's about 70 calories worth of peanuts, which won't always cut it)
- Make sure you can actually carry and lift your carry-on luggage. I was traveling with a laptop in my backpack, but the weight of it (in addition to other stuff I was carrying) has started to take it's toll on my back, so I'm finally leaving it at home. I wish I could say some nice person will help you if you are struggling to get your bag into the overhead compartment, but on the 10 flights I've taken the past few weeks I've only had one person offer to help (he was married and traveling with his wife and young child - clearly he knew how tough pregnancy can be)
- Be patient. Most of the time travel goes smoothly, but you never know what might happen. Just try and relax and don't let any surprises stress you out too much.
Enjoy your trip!