The Behaviour of the Cervix over the Ovulation Cycle

The cervix is at the bottom of the uterus and is connected to the uterus at the isthmus. Stimulated by the ovarian hormones the cervix produces several types of cervical mucus. The diagram at the right illustrates the various crypts from which the mucus secretions emanate. These have a crucial role in fertility and in the general health of the woman. Cervical mucus discharges at the vulva and can be felt and observed by the woman. This is the basis of the Billings Ovulation Method.

The behaviour of the cervix and the correlation with the symptoms at the vulva are explained below using animation.

More detailed commentary on each stage in the ovarian cycle is given in an accompanying sequence of static images.

Colour codes used in the cervix images

G mucus

L mucus

P mucus

S mucus

Menstrual flow

learn your fertility - know your fertility


Isthmus & Cervix

Billings Method



step by step