In this guide I’ll provide an explanation of your fertile window including an overview of cervical mucus to help you better understand how NFP works in practice and get you one step closer to your fertility goal.
First, what is a “fertile window”?
The group of days during your cycle in which pregnancy is possible is called your “fertile window”. Typical duration is 5-7ish days but the length of your fertile window can vary from woman to woman and even from cycle to cycle for the same woman. So which 5-7ish days is it? The fertile window includes the day of ovulation plus the 5 days leading up to it, since sperm can survive up to 5 days when the right conditions are present. Even though the egg itself only lives for 24 hours, your overall fertile window is much longer than that since we are including the full group of days when pregnancy is possible.
In essence, what you’re really asking is “when is ovulation”? You can tell that you’re ovulating and approximately when by observing your cervical mucus pattern and then combining that information with your daily temperature chart. When you look at both the cervical mucus and temperature info together you’ll get a big picture view of what’s going on with each specific cycle. And therein lies the beauty of NFP – it’s real-time, accurate info you can use each cycle, not a guess or estimation or prediction based on averages from other women.
Why should you care?
Understanding what your fertile window is and how to identify it is THE KEY to effectively practicing natural methods of family planning. If you want to ditch the pill and/or any other type of hormonal contraceptive – OR – if you are actively trying to conceive and want to maximize your chances, you will want to make friends with your fertile window. In fact, the entire effectiveness of the method is based on your ability to correctly identify the beginning and end of your fertile window, each and every cycle.
Pinpointing your fertile days is all about accurately identifying your mucus pattern.
For any amount of reliability on this one you have to get really good at observing (and recording!) two things:
- The sensation you feel “down there” when cervical mucus is present
- What you actually see (on your toilet tissue paper when you wipe in the bathroom) on the days when cervical mucus is present
The concept that cervical mucus (or cervical fluid, if you prefer to call it that) comes out of your vagina every cycle makes some women feel grossed out. When I first heard about NFP in my 20s I was totally disgusted at the thought of cervical mucus even existing, let alone the idea of having to intentionally observe it and interact with it. But the truth is that your mucus is the key to decoding your fertility. It took years before I really started to embrace the idea of consistently recording my mucus observations. If you feel similarly at first, I encourage you to get over it as fast as you can. Just remember that it’s a completely normal, healthy (and necessary!) bodily function that can tell you a great deal about your fertile health.
Here’s what you need to know:
- Throughout your cycle your cervix is constantly changing. Specifically, there are three differences that happen as you enter the fertile window: your cervix will gradually go from firm to soft, shift from a low position to higher up, and the opening will go from being closed to more open. All of that is happening internally.
- Around the time of ovulation, your hormones will cause the production of cervical mucus, which you can see externally when it comes out the vagina. You’ll notice it on the tissue paper when you wipe while using the bathroom.
- Tracking the changes in your mucus consistency provides a reliable way to know when pregnancy is possible.
- Sperm cannot survive in the acidic environment inside the uterus without the presence of mucus – they die within hours. But WITH the presence of mucus, sperm can live up to 5 days in there.
So what do you need to do?
After your period ends, start watching for mucus to show up and last for several days. First, be conscious about the sensation you feel and consider the following words to describe what you might experience:
Feel: Wet – moist – sticky – damp – slippery – itchy – dry
Second, start watching for mucus to appear when you wipe when using the bathroom. You will readily see it on your toilet tissue paper. It will change consistency over a period of several days until it eventually dries up. Some words to describe what you might see are:
Color: white – clear – yellow – cloudy – opaque
Consistency: tacky – watery – stretchy – egg white – lubricative – creamy – thick
Amount: more or less
Record what you see every day in your fertility tracking app. If you see different kinds of mucus throughout one day, just record your overall “most fertile” mucus type for that day. (TIP: For suggestions on which app, check out my post here.)
Eventually you will notice that your mucus will increase/become more like clear egg white and then within a few days it will change back again to a more tacky consistency. It is especially crucial to record what you see on the days your mucus changes. If it looks different from yesterday that’s when you definitely want to pay attention and get it recorded.
Below is an example of how you might record a typical mucus pattern in a chart format:
The highlighted days 10-16 when this example person observed mucus fall within the fertile window. (Note that for avoiding pregnancy we wait a few additional days after mucus starts to dry up in order to account for any variations in ovulation timing. If your current goal is to avoid pregnancy make sure you get educated on how to properly practice NFP – it can seem confusing at first and I encourage you to learn from an instructor!)
Each row on the left is labeled so this person is recording what she feels, what she saw, and how it looks. The abbreviations used in the example above are as follows:
t = tacky w = wet m = moist p = period days d = dry day
– = some mucus present + = more mucus present
Notice the pattern: there is a distinct change from less fertile mucus to more fertile and then back again to less fertile, before the mucus eventually dries up altogether and is no longer present for the rest of the cycle.
In this example, the most-fertile days happened on days 12 – 14. So those are the days when a pregnancy is most likely.
The Bottom Line:
It can take a few cycles of practice to feel confident making your own mucus observations, so give yourself the time and space to work on making it a habit. Creating reminders to think about it and then learning to be conscious of the sensations you feel throughout the day may take a little trial and error before you find what works best for you. But before long it will become just part of your daily routine.
A special note when trying to avoid pregnancy: Learning how to correctly identify the end of your fertile window also takes some practice, and I encourage you to seek out quality instruction to fully understand the NFP method before making any choices that may have a lasting impact (such as should we have sex tonight?). Based on years of research, scientists have learned how many days post-mucus you should wait before you can consider yourself infertile again at the end of your cycle. It takes some time to fully explain how to know when you’re infertile and that subject is beyond the scope of this guide.
That said, if you’re ready for more I’d love to help you learn NFP, so you can feel confident in reaching your fertility goals without drugs, devices or chemicals. For more information, check out my page here.
I invite you to schedule your
completely free 30-minute
Natural Fertility Discovery Session
with me to find out if NFP is a good fit for you.