Ive been twice at around 20 weeks, and fortunately, as we are fairly regular visitors, I felt I knew what was safe for me and what wasnt.
I did do Kilimanjaro Safaris, Kali River Rapids and a few others that Disney dont recommend for pregnant women. Obviously, I kept away from the "Mountains" and anything with a big drop like TOT or high G forces like R&RC.
I think its all down to personal choice. Get a partner or friend to ride something first that you arent sure about. I think Disney are quite over cautious with some of the ride restrictions, but they do have your best interests at heart. As you are in a fairly early stage of pregnancy (and the most vulnerable trimester) then I wouldnt go "mad". There are lots and lots of attractions that you can do safely, and you wont feel you are missing out on much thats for sure.
Good luck with your pregnancy.
Allie