I agree, there is no way to tell how you will feel. Personally, I wouldn't do it. Now, this is coming from a person who exercised intensely throughout 2 pregnancies, was young, fit, and healthy. That is, until at 32 weeks, I went on a neighborhood ride with my DH and 2 year old, had a little wobble, probably due to my protruding abdomen, and jammed the end of the drop bar into my stomach. One week later, I went into labor. I was able, with the help of drugs, staying at home, and my mom moving in with us for 3 weeks, keep the little racer in there until 36 weeks, when they deemed it safe for delivery.
Make an informed decision for you, but I learned the hard way, that everything changes when you are responsible for a pregnancy. This was 28 years ago, and I wish I had not gone on that ride!