I'm pregnant, 26 weeks, and going to thailand next week, yay! I was booked in to have my hep A booster, as I had all the jabs last year, but they told me to wait until I was further along in the pregnancy, I was about 12 weeks then.
So, I went the other day to get it, and they pretty much advised me not to. The nurse called the manufacturer of the hep A vaccine, they said that they wouldn't advise to have it, because they haven't done any research on it's effect on pregnant women. There may be no evidence that it is harmful, but that's only because they haven't tried to find any!
So, because I had the original vaccine last year, the nurse said just to be careful what I eat etc. I think if I had insisted she would have done it, but it would be a bit of a worry, and because I had it last year I'm going to go without. I was a bit irritated tbh, because I had rearranged my whole day to go in for the bloody thing, and my GP had told me it would be ok because it's not a live vaccine.
Anyway, my situation is slightly different to yours, I don't know what jabs you have had in the past, and it really will depend on where you're going and what kind of places you'll be staying. Just go ask your GP, and talk to the nurses as well, they may not want to do it for you regardless of what the GP tells you. I had another appt to get it done, and they nurse flat out refused to do it for me because she hadn't looked into it. Couldn't be bothered to either, apparently!
Have a wonderful holiday, I plan to!