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What is Cervical Mucus and Why is it Key to Fertility Awareness and Cycle Tracking?

Cervical mucus (also called cervical fluid, CM or CF) is the primary sign of fertility and plays an amazing role in our health and fertility. Along with tracking your BBT, tracking your cervical mucus will give you unbelievable insight into not only your fertility but also your overall health. The ovulation and menstrual cycle is the fifth vital sign for women.

CM is produced in the cervix, which is the opening to and base of the uterus and is situated at the end of the vagina. The cervix contains something called cervical crypts, which are what create the different types of cervical mucus that we have. Under the influence of our sex hormones, specifically estrogen and progesterone, the crypts produce the different types of cervical fluid.

Now before we go on, you should know this important rule of thumb: if you ever see cervical mucus through your charting observations prior to confirmed ovulation (usually through an external check that involves wiping front to back over the vulva with a clean finger or a folded tissue) you should always consider yourself to be fertile plus a count of 3 days.

What You Need to Know about Cervical Fluid

Cervical fluid serves two main purposes: to sustain and move sperm when you’re fertile and to protect against infection both when you’re fertile and infertile.

First, it creates an alkaline environment in the normally sperm-killing acidic vagina, which allows sperm to survive. It nourishes the sperm and also filters out any that are defective. Cervical mucus becomes more wet and slippery as ovulation approaches and, under the influence of a surge in estrogen, it develops swimming lanes that propel the sperm closer to the ovum (egg) that’s released at ovulation. This cervical fluid gives a smooth, wet, or slippery sensation at the vulva. It may look cloudy or clear, and may be creamy (like lotion) or stretchy like egg-whites - or somewhere in between. Without cervical mucus, the sperm wouldn’t be able to swim fast enough to reach the ovum and would die!

This is why having cervical mucus is so key to conceiving. If you are experiencing scant or no cervical fluid, you may have a hormonal imbalance or nutritional deficiency. Many women also experience less optimal cervical mucus after using hormonal birth control and may experience a decrease in cervical fluid with conditions like bacterial vaginosis and yeast infections (and some STIs). Don’t worry, cervical mucus quality and consistency can be improved!

Second, cervical fluid protects the uterus and reproductive organs as a whole from infection. After ovulation (and sometimes before the fertile window opens, depending on the length of a particular woman’s cycles), progesterone is the dominant hormone. Progesterone causes the cervix to produce a different fluid, which becomes a dense plug that closes the opening of the cervix. This plug is impenetrable to sperm and harmful bacteria. When this cervical plug is in place, you should observe a dry sensation at the vulva. You generally won’t see any cervical mucus when this plug is in place and, if you do, then you may have a hormone imbalance in need of attention.

You may notice some white, dry lines in your underwear (along with a dry sensation at the vulva) even during your infertile phases. Not to worry! This is simply vaginal cell slough and is how the vagina sheds its dead epithelial cells. Vaginal cell slough is not cervical fluid. It’s how the vagina self-cleans and keeps its environment balanced.

So once you have learned how to observe and chart your cervical mucus, ideally from a trained educator as this yields the highest efficacy rates, how do you use this sign to either get pregnant or avoid pregnancy?

Justisse Method and FABM

In general, you can expect four stages of cervical fluid, dry with a dry sensation, non-peak with a smooth sensation, peak with a lubricative or slippery sensation, and then a return to dry after ovulation. 

If you are avoiding pregnancy, make sure to abstain or use barrier contraceptives as soon as you see cervical fluid. You will continue to abstain until you have observed 3 days in a row of dry sensation and no cervical mucus, plus a BBT temperature shift sustained for at least 3 days.

Now, note that this recommendation is based on the Justisse method which broadly considers all preovulatory cervical fluid to be fertile. This is on the more conservative side when it comes to avoiding pregnancy with FABMs. Whichever FABM you ultimately choose, the most important thing is to stick with that one method and follow its rules exclusively.


Cervical Mucus

If you are trying to conceive, you’ll want to start having sex as soon as you see moist cervical fluid after menstruation. Every other day is generally enough. While not necessary, some women also take LH or OPK tests to look out for the luteinizing hormone surge that comes right before ovulation. If you take these tests, you can switch to making love every day if you get a positive. Continue having sex until ovulation is confirmed. An ovum lives for 12-24 hours, so try to also have sex on the first day after your temperature has risen.

You may sometimes have stop-and-start cervical mucus patterns without a BBT shift. Without the BBT shift, you’ll know that you haven’t ovulated yet even if your cervical fluid dries for a couple of days. This is likely your body trying to ovulate and just not quite getting there yet (perhaps due to stress or travel). If you’re trying to conceive and haven’t seen a BBT temp shift yet, you can still view every day of cervical fluid as fertile and continue to have sex.

Tracking Cervical Mucus - Be Consistent

Finally, it’s recommended to track cervical mucus by checking every single time you go to the bathroom. At the end of the day, you record the most fertile cervical fluid you saw during the day. You can do this either in an app (without predictions) or on a paper chart. Be consistent in how you check, for example by only checking externally by wiping front to back over the vulva. It can take a little time, but developing this habit is key!

If you'd like to learn more about FABM, including how to chart your cycle and identify your fertility window, download Tempdrop's free Introduction to Fertility Awareness, a beautifully-designed guide written by seven certified educators (including Sophia!).

Sophia Zaferes, Fertility Awareness Educator

Sophia Zaferes is a passionate advocate for Fertility Awareness and holistic women’s health and self-studied for many years before making the jump into a two-year master’s level program through Justisse College International to become a Holistic Reproductive Health Practitioner. While she has taught FAM for a few years now, this program is deepening her knowledge and equipping her to better serve the women she works with. Other passions include natural childbirth and pregnancy, herbalism, and non-toxic living - all of these inform the information and services she provides. She lives with her husband and cat in their little apartment.

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