Last time I was pregnant was 20 years ago tomorrow. I sold my horse and quit riding, which I had been doing daily, when I was about 3 months. My mid-wife didn't tell me to, but I really didn't want to in any way create a bad situation, namely a horse accident. I would feel the same about cycling; accidents happen and you have more than your own life to consider now. Although you won't believe it when you hit 8 1/2 months, pregnancy is not a terminal condition and finding a very low risk activity until D-day might be worth considering.