We went to Blizzard Beach with our 12 year old nieces when I was 8 weeks pregnant. I believe almost all the slides had restrictions. If I remember correctly I did do teamboat springs because I had been on it before and thought it was fairly gentle but stayed off all the other slides. If I had been further along, I probably wouldn't have done that one slide either though. I wouldn't even recommend the wave pool at TL because I have gotten a few good kicks when the pool was fairly crowded and left the park with bruises. After that experience, I wouldn't want to risk having someone kick me in the stomach.
Like the pp said, if your kids are younger, then you could hang out with them in the kiddie area. Both TL and BB have a lazy river you could float around on (they provide innertubes) and there are places to sit everywhere so if you have a partner then you can relax with a good book while they play. Unfortunately I don't think their's a ton of fun things for expectant moms to do there, at least that is what I found.
hth, and congrats on the pending arrival!
Cheryl