I have not been pregnant at WDW, but did go on a big overseas trip at 32 weeks
If you are flying, anything over 32 weeks requires a doctor approval, so make sure you check with yours.
I was very active and had a great pregnancy (I went to the gym until week 38 and went to work feeling fine the day before my due date) and the long flight took a toll on me. Even drinking lots of water and getting up frequently my feet got pretty swollen
Once in Disney you can take it easy if you need to, not sure at what time of the year your trip is, but heat and crowds will probably won't go well with being 33 weeks.
Every pregnancy is different, but I will check with your doctor. I asked mine and she was fine with me going at 20 weeks and not so keen after 32, because for me it is a long flight