I went twice during my last pregnancy and had a great time. The biggest thing I’d recommend is going in cooler weather if possible, drinking LOTS of water, and taking breaks throughout the day. I was in pretty good shape at the time, but that could also be a factor.
I was pleasantly surprised by all of the rides I COULD ride while pregnant. The only things I couldn’t go on were coasters (naturally), and some spinny things. It was actually a really fun trip - I slowed down and took in more of the shows and boat rides than I normally would’ve. Hope you have a great trip.