8
2: Pinpointing the Peak
The last day of the slippery sensation is the most fertile day of your cycle. It is called
the Peak of fertility, and is very close to the time of ovulation. You can be sure that
if you recognise the Peak of fertility then you have identified the time very close to
ovulation.
Just before ovulation another hormone called
progesterone starts to be produced. This
hormone prepares the lining of the uterus
in case there is a fertilised egg ready to
implant. Progesterone also causes changes
in the cervical mucus. It activates the cervix
to produce the thick, impenetrable mucus that
forms the plug in the cervix. It also activates
the reabsorption of fluid from the mucus so
that the slippery sensation disappears. So it
is the rising level of progesterone that causes
the abrupt change in sensation that helps you
identify the Peak.
It is important to realise that
the Peak is not necessarily
the day of most mucus.
The amount of mucus may
decrease but the slippery
sensation may continue for a
day or two— the sensation is
the most valuable symptom.
