Mucus methods

Mucus methods are based on daily observation of the mucus secretions at the vaginal introitus, as well as a sensation of wetness or dryness at the vulva. The observed patterns allow the menstrual cycle to be divided into postmenstrual infertile, ovulatory fertile and postovulatory infertile phases. Variations include the Billings Ovulation Method and the 2-Day Method.

Unprotected sexual intercourse is avoided on the days of subjective heavy menstrual bleeding. Intercourse is permitted on alternate days during the postmenstrual infertile phase, and avoided once the fertile phase is detected and until 3 consecutive days of dryness.