Unlike the RU-486 pill, the Plan B pill does not cause spontaneous abortions. The Plan B pill works by delaying or prevention ovulation so young girls can’t get pregnant. The Plan B pill must be taken within 72 hours of unprotected sex. On Tuesday the Food and Drug Administration (FDA) approved the sale of Plan B, the morning-after pill to girls as young as 15, without a prescription, and without parental permission. The Plan B pills will be available at your neighborhood pharmacy for sale over the counter.