I found this article about prenatal exercise to be very informative. I can attest that I wasn't exactly an exercise buff before my pregnancy, but I really wanted to try to do the right thing about staying healthy during my pregnancy; however my fears about "hurting" the baby hindered my ability to establish a healthy workout routine. Check it out and let me know what you think.
The Truth About Prenatal Exercise - Now that you’re pregnant, are you afraid to start or keep exercising? This myth-busting information will help you get the activity you need. - Fit Pregnancy