Symptoms-based methods involve tracking one or more of the three primary fertility signs - basal body temperature, cervical mucus, and cervical position. Systems relying exclusively on cervical mucus include the Billings Ovulation Method, the Creighton Model, and the Two-Day Method. Symptothermal methods combine observations of BBT, cervical mucus, and sometimes cervical position. Calendar-based methods rely only on a history of cycle lengths. While the World Health Organization classifies both symptoms-based and calendar-based methods as "fertility awareness", some teachers of symptoms-based methods do not consider calendar-based methods to be fertility awareness.
Systems of fertility awareness may be referred to as fertility awareness-based methods (FAB methods); the term Fertility Awareness Method (FAM) refers specifically to the system taught by Toni Weschler. The term natural family planning" (NFP) is sometimes used to refer to any use of FA methods. However, NFP specifically refers to practices that are approved by the Roman Catholic Church: breastfeeding infertility, and periodic abstinence during fertile times. A method of FA may be used by NFP users to identify these fertile times.
Women who are breastfeeding a child and wish to avoid pregnancy may be able to practice the lactational amenorrhea method (LAM). LAM is distinct from fertility awareness, but because it also does not involve devices or chemicals, it is often presented alongside FA as a method of natural birth control.