The average American woman—who wants two children— spends about three decades trying to avoid pregnancy and only a few years trying to become or being pregnant. Sexually active women who are not seeking pregnancy may nonetheless practice contraception poorly or may not use a method at all. A wide range of reasons explain this seeming contradiction, including personal feelings and beliefs; experiences with methods; fears about side effects; partner influences; cultural values and norms; and problems in the contraceptive care system. Helping women prevent unintended pregnancy requires a broad-based approach that addresses many of these issues.