The average American woman’s life plan has changed drastically over the last few decades. It’s no longer start having sex, get married, and have a kid…all within 4 years. It’s now start having sex…continue having sex for about 9 years…then get married and have a kid in the year after that.
This means young women will need effective birth control for many years until their plans change.
Reference: Infographic from Guttmacher Institute’s Media Center. Based on data from: Finer LB and Philbin JM, Trends in ages at key reproductive transitions in the United States, 1951–2010, Women’s Health Issues 2014, 23:e1–e9.