How to find your Fertile Window

Did you ever learn that there is a small period of time in your cycle when you CAN get pregnant? You cannot get pregnant by having sex just any day of your cycle.  I know, I know, we were always told that having sex any day of your cycle can result in a pregnancy. Trust me, I lived by the scare tactic most of my life. Until I went to try and get pregnant and learned that this is just NOT the case. Seriously, there is only about 5-7 days out of your whole menstrual cycle that you can get pregnant! Ready to learn how to find those days in your chart? Whether you’re trying to conceive or avoid pregnancy all together, understanding how to find these days can make the difference between medical intervention and trusting your body to do the work it was made to do.

What is your fertile window?

The first half of your cycle is the time when your ovaries are preparing a new egg follicle for ovulation. As that egg follicle begins to mature, hormones in your body begin to amp up to initiate the response outwardly, making you aware that ovulation is about to happen and you are currently fertile. Your body naturally makes you fertile for about 5 days leading up to ovulation and for up to 24 hours after ovulation occurs. 

How does it work?

As estrogen levels rise leading up to ovulation, they send messages to your cervix to tell it to prepare for the impending attack of sperm.  By doing this, your body is naturally creating an optimal environment for fertilization to occur.  Remember – your uterus WANTS to get pregnant, this is it’s literal goal every single cycle and why you have the ability to make it happen every single month. You entire body will function optimally when your hormones are balanced and your menstrual cycle continues without a hiccup.  If you are having trouble with irregular cycles, check out my 1:1 program for enhancing fertility and balancing hormones. 

When does it happen?

This will vary from person to person. Generally, the first day of cervical mucus will signal the beginning of your fertile window, and ends 24-48 hours after the ovulation occurs. Where this lands in your chart may look completely different than your best friend. If you ovulate on CD 16, your fertile window may look like CD’s 11-17. This can change from cycle to cycle since ovulation doesn’t always occur on the same day every month.

Other things that can affect accurately identifying your fertile window include estrogen dominance, low estrogen levels, irregular LH levels, and stress. 

What goes on during the fertile window?

Rising estrogen levels stimulate the cervix to create cervical mucus and to change position in order to increase chances of any sperm meeting an egg. 

LH levels rise and reach a peak, initiating the release of the egg from the ovary. 

After the egg is released, it will travel through the fallopian tubes into the uterus. It is on this path that it can come into contact with sperm and potentially experience fertilization. 

Using your body to identify your fertile window.

Cervical mucus

This is produced by specialized cells inside your cervix. This mucus supports sperm by providing it nutrients to continue developing, acting as a filter for removing poor swimmers, and by providing a transport system to help shuttle them along through the cervix. sperm can stay alive for up to 5 days in cervical mucus. During the fertile window you may notice 2 different types of mucus:

  1. Creamy, sticky, off white = non-peak mucus
  2. Clear, stretchy, slippery, looks like raw egg whites (AKA egg white cervical mucus (EWCM)) = peak mucus

Non-peak mucus will present itself early on in the fertile window, and signals that your body is preparing for ovulation. Peak mucus will show up the 2-3 days before ovulation and possible the day after and correlates as the optimal fertile sign. 

Cervical position  

In response to the circulating hormones, your cervix will change positions depending on your state of fertility. During the fertile window and ovulation, your cervix will appear high, soft, and open, kind of like touching slightly parted lips. Outside of the fertile window during your luteal phase and early follicular phase, your cervix will appear low, hard and closed, like touching the tip of your nose. The best way to get better acquainted with your cervical position is to check it every time you take a shower and record your findings in your chart. 

Basal Body Temperature  

Your temperatures leading up to your fertile window do not change or provide you any detail into the fertile window, but it will tell you exactly when ovulation occurred. 


Your moods naturally sway with the phases of your cycle thanks to the influence of hormones on your neurotransmitters and brain. During your fertile window and ovulation you may experience a boost of social interaction, confidence, and increased sex drive. Many women admit to feeling horny during the fertile window, which makes complete sense. The increasing testosterone and estrogen work together to increase sex drive and naturally increase your chances of getting pregnant by making you feel like having sex. You may also be able to reach orgasm faster and with a greater intensity during this time. 


Just like your moods, your energy levels change throughout your cycle as well.  Your energy levels are at their highest around ovulation making you feel like going for a run or having marathon sex, when these activities are otherwise unattractive to you in the other phases of your cycle. If you notice a natural increase in energy in addition to any of the other symptoms above, this could be a sign that you are approaching ovulation.

Ovulation Predictor Kits - OPK's

What are they?

These are test strips that can give you insight to when ovulation may occur. You can find their packages near the pregnancy tests at your local drug store and even Target. They work very similar to pregnancy tests as some women pee right on them, while others will dip them into a cup of urine – whatever your preference! 

How do they work?

OPK’s measure the levels of Luteinizing Hormone (LH) in your urine. This is the hormone that surges and stimulates the action of ovulation. You can start the strips the first few days of your fertile window and watch as the line begins to darken as the days go by. When the test line becomes as dark or darker compared to the marker line, this is considered your peak LH surge, suggesting ovulation will happen within 24-48 hours. 

What do they tell you?

  • LH levels are rising and your ovaries are preparing to ovulate an egg follicle
  • LH surge is the trigger to ovulate the egg
  • Can help you to identify the fertile window

What don’t they tell you?

If ovulation occurred. 

You can have an LH surge without ovulation actually occurring. Some women will experience delayed ovulation where an LH surge can happen but ovulation may not occur. There are some cases where women will be able to notice more than 1 LH surge or positive OPK throughout their cycle. This can also be associated with longer than normal cycles and irregular patterns of cervical mucus production. 

How can you confirm ovulation occurred?

  • Basal body temperature shift
  • Progesterone testing 
    • Blood
    • Urine

Are you having a difficult time identifying your fertile window or understanding charting? Are you getting tired of never knowing if you actually ovulated? Maybe you just want to learn more about understanding your cycle! Sign up for a free discovery call to see if you would be a good fit for my Cycle Charting Package where we work 1:1 to learn anything and everything from your personal chart! Click here to schedule today!

Let’s chat in the comments – what do you struggle with most when it comes to figuring out your fertile window???

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