The cervical mucus method can be used as a way to identify fertile times to help you gauge the best days to have or avoid unprotected sex. Tracking your cervical mucus for either fertility or contraception is inexpensive and doesn't have any side effects. Some women choose to use the cervical mucus method for religious reasons.
The cervical mucus method is sometimes combined with another method of natural family planning, such as tracking basal body temperature. This is sometimes referred to as the symptothermal method.