The birth control pill itself doesn't affect long-term fertility. In the short term, a small number of women will have a delay after stopping the pill until they start ovulating again. This is more likely if the woman is either under- or overweight or engages in heavy aerobic exercise. For most women, ovulation resumes about two weeks after the last pill is taken. There is no need to wait to try to get pregnant after pill use. The common recommendation to wait three months has no scientific basis.Depo-Provera is an injectable form of hormonal contraception. One injection provides protection against pregnancy for up to four months. But its effects on fertility can last up to two years. This is not a rapidly reversible contraceptive and shouldn't be used by women who wish to get pregnant within one year.