It's good you received some opinions both pro and con regarding riding while pregnant. Any forum is going to give you personal feelings and results that person had. However, the best source of information would be from your physician. I'm sure you know that. This was a good forum thread in many ways, but overall, the results were from personal experience. Everybody and body is different. Also, as your pregnancy progresses, your own body will change in form and ability to do things.
If you are having a pregnancy that is high risk... I'm sure your doctor would let you know and tell you how much to limit your activity. If you are enjoying a normal pregnancy and there are no complications involved, and your body is fit enough to do activities like riding a bicycle, and you are familiar with how to ride -- then go for it. Stay off the busy streets were traffic is a problem. Stay close to home. Take a cell phone with you in case you need help. Drink plenty of water. Enjoy your pregnancy -- it's a wonderful time of life!