The Fertile Window and getting to know your body.
The fertile window is the part of the menstrual cycle where you can get pregnant. It’s not every day of the cycle. Despite what sex-ed in middle school told us, someone who menstruates and has a female reproductive system cannot get pregnant any day of their life. Oddities occur seemingly outside the fertile window and under closer investigation it is usually do to irregularities in cycle length, such as a very short follicular phase and early ovulation.
To understand the Fertile Widow , we have to know that:
there are 4 phases with different hormonal characteristics and happenings
that ovulation is an event within the fertile window. It gets talked about as phase of the cycle, it is technically phase 3, and in reality it’s a 48-72 hour time window within the fertile window of the cycle.
that you can only get pregnant within your own particular window of fertility
The fertile window is most reliably tracked by tracking cervical mucus throughout your cycle. It follows a clear path of progression- which will be unique to each person in how it manifests. Nothing about the menstrual cycle is fixed from person to person. After menstruation (phase 1) we enter the follicular phase (phase 2) which is characterized by rising level of hormones, especially estrogen and FSH -follicule stimulating hormone-. This is responsible for literally stimulating the growth of follicules in the ovaries that will result in the release of an egg at ovulation. This is when FHS peaks and then quickly drops as we enter the luteal phase post ovulation.
THE DAY OF CHANGE is when due to this rise in hormone levels your cervical mucus starts to shift. This happens after menstruation in the follicular phase of the cycle. You go from mostly dry or very little discharge, to slick and wet (unrelated to arousal). This is most noticeable when you go to the bathroom and wipe and it’s different than the day before. This means you’re entering your fertile window and over the next days cervical mucus will go from:
watery or clear
to milky or creamy
to an egg white consistency and clarity (see through) signaling ovulation is happening within 24 hours. Egg white mucus is a signal of peak fertility.
it will then become more chunky and opaque meaning ovulation happened and you’re exiting the fertile window
once you experience the day of change until cervical mucus turns opaque and is no longer egg whitey, you are fertile and can conceivably conceive. Non physical factors apply so it’s not one and done.
This can be a window of 5-8 days depending on someone’s cycle length.
Some context. Fertile mucus is what keeps sperm alive in the body- due to high sugar content that looks like ferning under a microscope- and is what transports it through the cervix into the uterus. Sperm can live up to 5 days inside the body due to being fed by this high sugar content fluid. This is why the fertile window is a window of time and not a fixed point.
The length of your cycle and where you ovulate is what determines when you enter your FW. In a shorter cycle, it will be sooner after menstruation. In a longer cycle, farther away. In a cycle of about 27-29 days the day of change could happen anywhere from day 8-10 with ovulation happening around day 12-16. It is variable. And can change based on stress, travel, the moon, and things like moving, getting sick (immune function), and plant medicine work. That’s why we need to be able to track this for ourselves and not rely on an app that works off of an algorithm to do it for us. Some people naturally ovulate earlier, I’m one of those, and some people naturally ovulate later.
The fertile window and therefore ovulation, can change by a day. And depending on what you want to happen or not in terms of conceiving, this could make a big difference. Especially in the current atmosphere and climate of reproductive rights being under major threat in the US and in many countries around the world, having the knowledge of how fertility and conception works in the minds and hands of the ones who actually conceive is imperative.
A little example:
Let’s say you have the day of change on day 9 of your cycle. On day 10 or 11 you have unprotected sex and your partner finishes inside of you. You then ovulate on day 13 or 14. That sperm was being kept alive inside your body and has the potential to meet the egg that was released and fertilize.
Apps don’t know when you ovulate. They agragate the information you put in and then plug it into an algorithm and give you predictions.
Ok so what happens next?
After the event of ovulation when hormones such as estrogen and FSH peak, they quickly drop off about 24-48 hours later. This is why in Fertility Awareness Method you extend the fertile window that much time past ovulation. Like most things in the cycle this is also trackable. From the egg white mucus your discharge will become opaque and somewhat lumpy or chunky. It will make some noticeable change away from the egg white thing. This means hormone levels have dropped and you are coming out of the fertile window.
Unless you are very familiar with your cycle and with FAM this is not a reliable method of birth control.
If you’re not on hormonal or cycle altering birth control (ps they all are) your options are:
use a barrier method aka condoms when you’re in your fertile window
do other things besides intercourse
be smart... withdrawal is not a 100% safe precaution as there can be pre ejaculatory fluid released and in some cases this can contain sperm
act accordingly with your goals of wanting to or not wanting to conceive
If you are wanting to conceive this tracking of cervical mucus and knowledge of your body and cycle is ESSENTIAL to the process. It’s literally where you are able to conceive. And if you don’t want to get pregnant this is THE information you need to understand.
You can get a sense of this in the following way. If you know how long your cycle are as in from the time you start bleeding to the next time you get your period - count the day between periods- you can get a sense of when you ovulate by counting backwards 12-14 days from your period. The luteal phase (the phase after ovulation and before menstruation lasts about 12-14 days in a balanced cycle). Lets say you have a 27 days cycle, ovulation is somewhere around day 13-15. If you have a 30 day cycle it’s some where around day 16-18. A 25 day cycle it will be around day 11-13. Etc. Pay attention to cervical mucus in the week before this.
The other way, and I recommend incorporating this one because it’s in real time, is to track forward from your period. Track how many days you bleed for. Day one is when you have flowing period blood, aka more than spotting. Once you’re done menstruating pay attention to when that day of change comes, and then track the above things in this article. This will give you real time information about what is happening with your body.
This is important and useful information whether or not you’re sexually active and whether or not you are intimate with partners where you can get pregnant. This is self and body knowledge that goes way beyond conception. More on that another time.
This comes back to being comfortable to interact with our own bodies. This is information for us to be the keepers of.
Happy tracking, love Zara