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APRIL, 2022


This blog is for educational purposes only. Do not begin relying on any fertility awareness based method without proper guidance from a trained professional. 

Let me start off by explaining that there is not just one fertility awareness method – there are many fertility awareness based methods (FABM) that fall under the umbrella term “fertility awareness method.”

FABM's are sets of practices that are used to determine the fertile and infertile phases of your menstrual cycle, which can be used to achieve or avoid a pregnancy. Cool, right?! This is done by tracking your fertile biomarkers that change in response to daily hormone fluctuations throughout the menstrual cycle (1): your cervical mucus (CM), your basal body temperature (BBT), and your cervical position (CP).


Note: FABMs are not the rhythm method: your fertile signs and symptoms must be monitored daily as they will fluctuate from cycle to cycle (2).


There are several FABM that have curated different strategies to monitor your body’s fertile signs (2,4):


The Billings and Creighton methods choose just to use the tracking of cervical mucus. They require that every day of your cycle, you observe and record the sensation, appearance, or the absence, of cervical mucus. Unlike other methods, you are not required to record your BBT or cervix position. 


Both Billings and Creighton require a high level of attention to detail- the difference between the two is where your attention is directed. Billings does not require touching or finger testing of your cervical mucus, rather the emphasis is put on the sensation at your vulva when wiping plus a keen attention to the sensations that occur throughout your day. Creighton is more in depth as it requires wiping from your perineum + touching and finger testing your cervical mucous to get a strong sense of its color and consistency. Creighton also uses something called NaPro Technology, a science based methodology to maintain and diagnose reproductive issues.

Read more here:




Sympto-thermal methods utilize multiple fertility markers, compared to the first two that only track cervical mucus. The second main marker carefully observed in this set is basal body temperature and the changes in your cervical positioning. While all sympto-thermal methods consider CM + BBT at the very least, the difference between the methods being two things: 1) the rules they’ve created to determine infertile vs. fertile days + how to confirm ovulation and 2) if their method of tracking CM is standardized, meaning if it uses a strict and detailed protocol for recording and interpreting.

Here are a few examples of sympto-thermal methods:







Sympto-hormonal Methods differ by bringing in hormone testing monitors to test your hormone levels, rather than solely relying on interpreting the fertility markers your body presents. Both Marquette and Fertility Education and Medical Management (FEMM) use outside equipment to test your luteinizing hormone (LH). Marquette uses the ClearBlue Easy fertility monitor to mark the start and end of your fertile wave, and FEMM uses an LH strip to pinpoint ovulation.


Read more on each of these here:




Innate Rhythm is certified to guide you in FAMM, a method adapted from the Justisse model and curated by the renowned Lisa Hendrickson-Jack, owner of Fertility Friday and author of The Fifth Vital Sign

Besides helping you avoid or achieve pregnancy, we specialize in helping you chart and interpret your fertile signs to use as a window into your overall health.


If this is what you're looking for, read more about our private 16-week Immersion package here.

Your body's 3 main fertile signs explained:



Basal body temperature (BBT) is the measure of your resting metabolic rate. Your metabolism changes throughout your cycle in response to your reproductive hormone’s estrogen and progesterone. 


Prior to ovulation, your metabolism is slower which is reflected in lower temperatures, and after ovulation your metabolism speeds up and is reflected in higher temperatures. This distinct shift to higher temperatures will help you confirm that you have ovulated (2). 


Your body will predominantly be producing estrogen prior to ovulation. Estrogen is a building block hormone that will rebuild the endometrial wall that was shed during your last period. It also grows the follicles in the ovaries that contain a developing egg, stimulates cervical mucus production, and softens the cervix to allow cervical mucus to flow and sperm to enter. When estrogen is the main character, our metabolism is slower. This is reflected in a lower BBT throughout the first half of your cycle (3).


During ovulation, an egg is released from a follicle as a result of estrogen reaching its peak, which tells your pituitary gland to release luteinizing hormone (LH). Once released, the egg will only survive between 12-24 hours and will be reabsorbed back into the bloodstream if it’s not met by sperm. If it is met by sperm in this timeframe, conception can occur.


When tracking your BBT, you will be able to confirm ovulation after you see a consistent temperature shift showing higher temperatures in the second half of your cycle. This is due to a rise in progesterone, which leads to a faster metabolism and higher temperatures (3).


Post-ovulation, progesterone becomes the main character. It firms and closes the cervix and creates a cervical mucus plug to stop sperm from entering your cervix after you’ve already ovulated. It also suppresses ovulation for the rest of your cycle (3).


There are multiple factors that can affect your BBT – being sick, experiencing stress and anxiety, if you consume alcohol the previous day, traveling and changing time zones, and disturbed sleep (5).




Cervical mucus is a fluid produced in the cervical crypts of the cervix by the rise and fall of estrogen and progesterone. Its role is to prepare and care for sperm that enters the vagina so it can fertilize an egg once it’s released at ovulation. It does this by housing the sperm for up to 5 days if the cervical mucus is optimal, filters out defective sperm, and prepares sperm for fertilization. 


There are 2 main types of categories for cervical mucus — E-mucus and G-mucus.


E-mucus, or estrogenic mucus, is the type of cervical mucus that is stimulated by the rise in estrogen before ovulation that helps to transport and provide the appropriate environment needed for sperm to mature so it can fertilize an egg.  It’s the type of cervical mucus you will be checking, charting, and interpreting every cycle because this is the main indicator your are in the fertile window, of your cycle (6). It could vary between sticky and cloudy to clear and stretchy, resembling egg whites (2).  During this fertile window, the cervical mucus changes the pH of our vagina to be a perfect environment for sperm (7).


E-mucus is complex and has 3 different subtypes that go beyond the scope of this specific blog post, that one is coming — stay tuned!


G-mucus on the other hand is a type of mucus produced by the rise of progesterone in the second half of our cycle after ovulation. This mucus inhibits sperm from maturing so it can’t fertilize an egg and it physically blocks the passage of sperm by creating a cervical mucus plug to do this (8). This cervical mucus is able to inhibit sperm by changing the pH of the vagina. Outside of your fertile window, your vagina has an acidic pH which will essentially kill all of the sperm it comes into contact with (7). If this isn’t mind blowing then I don't know what is!!


When checking for cervical mucus, it’s important to identify what type of cervical mucus is present and also to identify if there is no cervical mucus, meaning you are experiencing a dry day. This will help you distinguish between your fertile and infertile days. 




Checking for cervical position is to check when the bottom of your cervix is open to help  identify your fertile window. During your cycle, the cervix will shift its position depending on if you are in your fertile or infertile window. 


When you are in your fertile window, the position of your cervix will be in line with the vagina, and you will be able to feel the opening of it. When you are in the infertile window, the cervix’s position will be tilted towards your rectum so you will not be able to feel the opening of it. This makes it almost physically impossible to get pregnant. Checking your cervical position is often seen as optional when you’re already tracking your basal body temperature and cervical mucus (2).


NOW let's put it all together.


You are only fertile up to 6 days in your cycle (6).


We know, we couldn’t believe it either when we first learned this. I mean, why isn’t this taught to us from a young age?!


Being fertile for only 6 days out of your cycle means the rest of the days in your cycle you are infertile, aka you can’t become pregnant. 


This is because when we ovulate, a mature egg being released from the ovary, the egg can only survive for 12 to 24 hours. Your body produces cervical mucus before we ovulate to help sperm survive for up to 5 days in hopes that it gets fertilized and you can become pregnant (6).


When that sperm-friendly E-type mucus isn’t present, it is physically impossible to become pregnant and sperm would die within hours. This is due to the acidic environment your vagina has naturally without cervical mucus present. Additionally, the position of the cervix will be tilted towards the rectum and the opening will be closed during your infertile days.


Sympto-thermal methods are 99.4% effective with perfect (9). Perfect use means that the method is used correctly and consistently every time (10). For typical use, the effectiveness ranges from 85.0% - 98.0% depending on the method used (9). Typical use means that the method is not always used correctly or consistently (10).


The skills you will learn will be your ally through reproductive and life transitions, like preconception, pregnancy, postpartum and lactation. You'll have a front row seat to the clearest window into your health and vitality right in the comfort of your own home.


If you’re interested in learning FAM, I would encourage you to sign up for my 16-week Immersion package where I will teach and guide you in practicing FAM, give you personalized nutrition for your body and hormones, and empower you by increasing your body literacy.



Updated March 2022

Written by: Jessica Guerra, Intern for Innate Rhythm. 

Revised by: Haley Smith, MSN, FAMM Owner of Innate Rhythm 




1. Thijssen A, Meier A, Panis K, Ombelet W. 'Fertility Awareness-Based Methods' and subfertility: a systematic review. Facts Views Vis Obgyn. 2014;6(3):113-123.


2. Smith, Haley. “What is Fertility Awareness?” Fertility Freedom Self-led Course. Video, 02/22/2022.


3. Smith, Haley. “Your Menstrual Cycle.” Fertility Freedom Self-led Course. Video, 02/22/2022.


4. Peragallo Urrutia R, Polis CB, Jensen ET, Greene ME, Kennedy E, Stanford JB. Effectiveness of Fertility Awareness-Based Methods for Pregnancy Prevention: A Systematic Review [published correction appears in Obstet Gynecol. 2019 Feb;133(2):382]. Obstet Gynecol. 2018;132(3):591-604. doi:10.1097/AOG.0000000000002784


5. Smith, Haley. “How to Check and Chart Basal Body Temperature.” Fertility Freedom Self-led Course. Video, 02/24/2022.


6. Smith, Haley. “How Yours and His Fertility Work.” Fertility Freedom Self-led Course. Video, 02/24/2022.


7. Hendrickson-Jack L. The Fifth Vital Sign: Master Your Cycles & Optimize Your Fertility. Fertility Friday Publishing; 2019.


8. Thijssen A, Meier A, Panis K, Ombelet W. 'Fertility Awareness-Based Methods' and subfertility: a systematic review. Facts Views Vis Obgyn. 2014;6(3):113-123.


9. Fertility Friday Instagram, Lisa Hendrickson-Jack

10. Cooper DB, Mahdy H. Oral Contraceptive Pills. In: StatPearls [Internet]. StatPearls Publishing; 2021.

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