It seems you're no one in this sport until you run the marathon. I've won three World Cross-Country Championships, and I only get a paragraph in Sports Illustrated. But it just doesn't seem to be enough. She was asked the question there, because she's a physician. That stuck with me for a long time.
Pregnancy is just another state of being.
You have to listen to your doctors, and do what feels right, but I kept running simply because I love running and feel best when I'm doing it. At one point in my second pregnancy, I had a small problem, and my doctor told me that I should probably stop running. So I did, and the next week I had a checkup with him. It showed that my blood pressure was skyrocketing. It was my release from everything else.