What is it like to travel while pregnant? It is really just like normal traveling only more people talk to you randomly and it is a bit less comfortable.
I have flown three times while pregnant. The first time was when we flew to LA for our cruise in January, It was still very early in the pregnancy so most people didn't even know I was pregnant, and I can't say I was uncomfortable because of it. The other two times were just quick trips to Buffalo and Syracuse. The worst part is that those plane seats in the full upright position are pretty uncomfortable when pregnant, so take off and landing was the worst part. The only 'official' person that said anything about the pregnancy was the lady to take my ticket as I boarded. She told me "don't give birth on the plane..no wait, I'm not going to be on it so do whatever you want". Even when I flew past the recommended cut off, no one asked how far along I was or really made mention of it at all.
I took the train to Albany and that was actually pretty comfortable, although people on trains are generally more chatty than people on airplanes. A lady sat next to me and we talked for a while, then she started talking with her friend across the isle so I picked up my book. When I closed my book as we approached Albany she started firing questions really quickly. Clearly she had been saving them up but didn't want to interrupt me. Pregnancy and baby's are a pretty safe topics so you really have to be prepared for the typical questions (1- When are you due?, 2-Do you know what your having?, 3- Have you picked out a name?,) and be prepared for people to tell you their opinions on your weight, belly size and position as well as get their stories about what they did when they were pregnant.
As far as car travel, I haven't really had any trouble riding in cars. No one will let me drive alone any more than 20 mins one way since I've been past 30 wks so driving a car is fine too. I generally have to recline the front seat a little more than usual and on long car trip put my feet on the dashboard. Mostly, I think it's the best way to travel while pregnant if you aren't going too far. Obviously, a 40 min flight is preferable to an 8 hour car ride. If you are a chatty person the train is a great option too, but if you are not into conversations with total strangers I don't recommend it.
Side note: Governor Pataki was on the train with me when I went to Albany. I choose to leave him alone since he got accosted a couple of times by people wanting to take a picture with him. Odd.