Cervical mucous (CM) can be used as a bare minimum for checking if you are approaching your ‘fertile window’. Using this sign alone is sometimes referred to as The Billings Method.
You will need to pay attention to the sensation at your vulva (does is feel moist, or dry?), any mucous that you can see on toilet paper after you have wiped yourself, and the consistency, colour and stretch. You can test by feeling the cervical mucous between two fingers and then moving the fingers apart to see if the mucous is tacky or maintains a stretch.
How does CM change?
Immediately following your period, cervical mucous is thick, scant and cloudy in appearance. There is little stretch. Some women describe the texture as being crumbly at this point. The vulva feels dry. The thicker, stickier, scanty mucous is very difficult for sperm to survive in, or swim through.
As oestrogen levels increase the mucous begins to change to a more cloudy, slightly more stretchy consistency. This is sometimes reffered to a ‘transitional mucous’. Some women also describe it as having a lotion type consistency. Again, this type of mucous does not support sperm.
In the days immediately prior to ovulation, the cervical mucous becomes much more abundant, thin, slippery and stretchy – like egg white. You will most likely to feel a moist sensation at your vulva. Egg white cervical mucous, EWCM, is the most fertile type of mucous, and it is when you notice this that conception is most likely. Ewcm supports sperm survival and also makes it easier for them to swim through the cervix and reach the egg.
Once ovulation has occurred, oestrogen levels fall and cervical mucous quickly dries up.