Cervical Mucus 101

What is cervical fluid?

Cervical fluid is just what it sounds like – fluid produced by your cervix. It is also referred to as cervical mucus, but since we find the word “mucus” one of the least-appealing words in the English language, most likely you’ll hear us referring to cervical fluid from here out.

Cervical fluid is completely natural, and nothing to shy away from talking about. It’s a normal, clean bodily fluid, like tears or saliva, that changes throughout your cycle to give you amazing insight into whether you are fertile or infertile. In fact, you have likely noticed cervical fluid since you were a teenager, but maybe just never really knew what it was or were taught what it meant.

Cervical fluid appears in response to the hormone estrogen. It helps make a woman fertile in three ways:

  • It provides a swimming medium for sperm
  • It provides nutrients for sperm to survive
  • It helps sperm live for days in a woman’s cervix area while waiting for ovulation to occur.

If there is no cervical fluid present, sperm lifespan is extremely short (hours long) because the normal vaginal environment is very acidic and hostile to sperm.

Typical cervical fluid pattern

The look and feel of your cervical fluid changes throughout your cycle in response to estrogen. Here is a breakdown of a typical cervical fluid pattern:

Before Ovulation: Directly after your period, your vagina gets a well-deserved break. You will experience dryness with no sign of fluid.

Approaching Ovulation: With ovulation around the corner, your cervical fluid increases as your levels of estrogen increase. It will often have a moist and sticky quality to it and it will likely appear white or cream-colored.

During Ovulation: Imagine going down a slip-and-slide that didn’t have any water on it. You wouldn’t get far, would you? Well in order to accommodate the sperm that dive deep into your cervix after ejaculation, your body produces more cervical fluid and even makes the path more slippery. You’ll notice your cervical fluid appear stretchy and clear. This type of cervical fluid helps sperm survive until ovulation occurs.

After Ovulation: Directly after ovulation, cervical fluid decreases, and most often, dries up completely.

Why the Fertility Awareness Method Works

The menstrual cycle is controlled by the interaction of hormones. Although it is not critical to understand how these hormones interact to practice the the Fertility Awareness Method, some women find that having a basic understanding of the menstrual cycle helpful if they are interested in learning more about why the Fertility Awareness Method works. Click here to skip this article on the menstrual cycle or expand “The Menstrual Cycle” section below to read more.

The Menstrual Cycle (optional article)

Here’s a less than two minute long video on youtube that gives a pretty nice overview of what happens during ovulation. If you’re having trouble viewing this video on youtube – check it out on Vimeo by clicking here.

The physical events of the menstrual cycle are primarily controlled by the interaction of hormones. Two of the most important hormones effecting the menstrual cycle are estrogen and progesterone.  The levels of each of these hormones change throughout your cycle due to events occuring within your ovaries. 

At the start of your cycle, protective bubbles called follicles start growing around 10 – 12 of the undeveloped eggs in your ovaries. These follicles secrete increasing amounts of estrogen as they grow. Once estrogen has reached a certain threshold, the estrogen signals your brain to release another hormone (known as lutenizing hormone) that will cause one of the follicles to erupt and release one egg from your ovary (or two eggs in the case of twins).

The leftover follicle that just erupted (the corpus luteum) now begins releasing the hormone progesterone.  Progesterone causes the lining of your uterus to thicken in preparation for the implantation of a fertilized egg.

The Fertility Awareness Method works by observing symptoms caused by estrogen and progesterone to identify what phase of your cycle you are in.  One of the primary outward signs of estrogen is it causes your cervical fluid to increase and become thin, clear, and stretchy.  Since this occurs before ovulation, this is helpful in identifying the fertile days before ovulation. 

Progesterone, which increases after ovulation, causes your basal body temperature to rise. Therefore, the Fertility Awareness Method uses your basal body temperature to identify when ovulation has occurred. If you are a visual learner, the following chart may help you understand further how these signs interact.  Please note that although this example shows a 28 day cycle with ovulation occurring on day 14, please keep in mind that normal cycle lengths vary and from 25 – 36 days and that your ovulation date is unique to each cycle.


Go to  next article – Observing and Recording Cervical Fluid >>