At the clinic I rarely met women, young or old, who understand their fertility and what happens during the menstrual cycle. They all know about the blood, although not always why they bleed. But few know anything about what happens between periods. No one has told them. Why have we kept this information from young women? Why do we tell them they can get pregnant any time of the month? If it's to encourage young people to use protection when they have sex, it doesn't seem to work.