Many women from my generation focused on building careers instead of a family through their 20s and 30s, and into their early 40s. At some point, the ticking of many of their biological clocks got louder, making these women suddenly worry about whether they could still get pregnant. In an ideal world, doctors would have had a medical method to determine how long before each individual woman started menopause and, thus, what the fertility level would be as they aged. (The average age of...