I think it is most always wise to consult with your doctor. Make certain you aren't at risk for any complications.
Beyond that, you may well not feel up to some rides you rode previously. Like nausea can arrive suddenly when you are pregnant. I also know my sister thought nothing of the safari ride, until she got on it and realized that being on it pregnant was a totally different thing that begin non-pregnant. Some ofthe posted warnings seem over the top, but most are there for a reason.
I also think it's important to consider the chance that a ride could break down while you on it. Something like Test Track may be okay if all goes well, but what if you get stuck on the loop part and it takes half an hour to evacuate you. Erring slightly on the side of caution may be prudent especially inthe case of attractions that are difficult to evacuate.
I think there is also some evidence which suggests that stress is bad fora baby. Some folks will be totally calm going on a given ride, while another will stress out and get their blood pressure up - so in that sense the answer to your question is also very personal.
One more point. I think everyone should make a point of staying hydrated inhe world, but I think it's especially important if you are pregnant. Also, you may well not want or need them, but it is wise to at lest know the location of the first aid and baby stations. You will be going it the cooler moths, so it's maybe less of an issue than going in the summer months - but those lounges can be a nice quiet retreat. OOh - and I kow you said you've been many times - but kowing the location of restrooms is also very helpful!
Anyhow, that's my two cents.