For the first 3-4 months after beginning hormonal contraception, irregular bleeding and spotting are a common side effect. This occurs as the lining of your uterus responds to the hormones and becomes thinner. It does not mean that the contraception is not working. You may miss your menstrual period completely with some forms of hormonal birth control. This does not mean you are pregnant, as long as you are using your birth control correctly. If you have any concerns about a potential pregnancy, please take a home pregnancy test and contact us for an appointment.