The Billings Ovulation Method (BOM) – also called the Billings Method, cervical mucus method, or ovulation method – is a method teaching women how to naturally time their pregnancy. In other words, it’s a way for women to understand their natural fertility signs through all their altering life stages – for instance, starting with puberty and ending with menopause.

When used effectively or in complete control over the method, a couple can avoid or achieve a pregnancy. When this method is combined with basal body temperature tracking, it’s called symptothermal method. Though learning the method is possible via books and journals, a certified teacher is still the best instructor. 

Australian husband-wife doctor pair, Dr. Evelyn and John Billings, developed this natural family planning technique in 1950 after observing several thousand women’s cycles to ascertain natural bodily signs during infertile and fertile periods. Contrary to other birth control methods, the Billings Ovulation Method doesn’t view infertility as a disease.

How Does the Billings Method Work?

Basically, the technique helps women understand their cervical mucus; how its texture, viscosity varies during the different days of a menstrual cycle; and what do those variables indicate.

Mucus consistency and quantity varies throughout a month. Generally, it is sticky and dry. With ovulation nearing, the cervix makes fertile cervical mucus, which tends to be much more slippery, wet and heavy in flow. A woman can feel the cervical mucus through her vulva. The Billings method teaches a woman to take note of the varying wet or dry vulva sensations during the month, documenting her feelings every day. This doesn’t entail feeling the cervical mucus with the finger. Any noticeable discharge on the underwear must be looked into as well.

A woman is fertile the most when she feels an increase in wetness at the vulva and sees more mucus discharge on her undergarment. Any unprotected sexual intercourse during this period means higher chances of pregnancy.


Since this is a form of natural pregnancy control, the Billings Method has several benefits over other not-so-natural birth control techniques.

  • The natural technique is not complicated and doesn’t cost anything. There are no hormonal drugs, body temperature recording, rhythm counting, or medical devices needed.
  • The Billings Method doesn’t come with the side effects usually associated with contraceptives or birth control pills.
  • Women charting their cycles are more likely to perceive bodily changes indicating other health issues such as thyroid issues, diabetes, etc.


This DIY approach may not work for every woman. Especially ladies, older than 30 years, will not find it easy interpreting their cervical mucus. These women may have to put their finger into play to determine mucus wetness variations (if any). Usually, most women require multiple instructional sessions for learning how to recognize secretion pattern during a menstrual cycle. 

The Billings Method is the most effective when women have accurate knowledge about the process. When equipped with incomplete knowledge about the process or if the cervical mucus signs are misinterpreted, practicing the method could lead to unintended pregnancy.


The procedure shouldn’t be used in tandem with unnatural birth control methods (such as patches or pills) because those may affect cervical mucus quality. During the method, it’s recommended to not indulge in sexual intercourse as there are chances of confusing semen and/or sperm with cervical mucus.