The Combined and Phasic Pills prevent pregnancy by
- Inhibiting the release of eggs from the ovaries (ovulation).
- Thickening the cervical mucus thus preventing the sperm from entering the uterus.
- Altering the inner environment of the uterus and making it impossible for the egg to attach to the walls of the uterus.
- Birth Control Pill - (http://kidshealth.org/teen/sexual_health/contraception/contraception_birth.html)