One method of fertility monitoring uses changes in cervical mucus to predict ovulation.
When a person is fertile, the cervical fluid is watery, thin, and slippery, and it may appear similar to an egg white.
What is cervical mucus?
Cervical mucus is fluid that the cervix releases into the vagina. It has several functions, including keeping the vagina lubricated and preventing infection.
Throughout the menstrual cycle, hormonal shifts influence the amount, texture, and appearance of cervical mucus.
There may be enough mucus for a person to notice it in their underwear. Although the cervix always produces some mucus, it makes more right before and after ovulation.
So, if a person notices an increase in vaginal discharge, they may be seeing fertile cervical mucus.
What is fertile discharge?
Fertile discharge is thin, clear or white, and slippery, much the same as an egg white. This type of discharge signals that ovulation is approaching.
Fertile cervical fluid helps sperm move up the cervix to fertilize an egg. It also keeps the sperm healthy during the journey.
People usually notice fertile discharge a few days before ovulation. The discharge may become wetter and more slippery over several days. After ovulation, the amount of discharge usually decreases.
A ripening egg grows inside an enclosure, called a follicle, in the uterus. The follicle grows and produces estrogen. When the follicle ruptures, the body ovulates, releasing an egg.
The estrogen that the follicle produces softens the cervix and opens it slightly. Estrogen also changes the texture of cervical fluid, making it more able to support fertility.
Cervical mucus timeline
Everyone’s cervical fluid is slightly different. So, to detect fertile discharge, a person should monitor their cycle for several months.
The days that discharge changes vary from person to person. Those who ovulate later in their cycle, for example, should expect fertile discharge after day 14.
In general, the cycle of discharge follows this pattern:
- Early cycle (days 1–5): This is when menstruation occurs.
- Post-period (days 5–10): At first, there may be little or no discharge, but sticky, glue-like fluid may follow. This is a time of low fertility.
- Pre-ovulation (days 10–14): The body starts to produce more estrogen. The sticky fluid may thin and look cloudy. Eventually, it gets slippery and begins to look like egg whites.
- Ovulation (day 14): On the day of ovulation, many notice that their cervical fluid is very wet and viscous. A person may be able to stretch the fluid an inch or more between their fingers.
- Post-ovulation (days 14–22): After ovulation, the body releases the hormone progesterone, which dries up cervical fluid. The discharge may look cloudy at first, then become thicker.
- Pre-period (days 22–28): As a period approaches, the discharge may have a glue-like consistency again. There tends to be little or no discharge 1–2 days before menstruation. Some people notice spotting just before their period.
Ovulation plays a significant role in determining the consistency of cervical fluid. A person who does not ovulate may notice fewer changes in their vaginal discharge.
A person who ovulates very late or early may find that their cycle does not follow the “typical” schedule.