Women are only fertile for part of their cycle. You may have been taught otherwise as a teen, but it’s true. We only ovulate once per cycle and the egg only lives for 12-24 hours.

Does that surprise you? If the egg is only alive for 12-24 hours, how does anyone get pregnant, right? But people do. Even when they are trying really hard not to sometimes.

The reason for that is because your fertile window is actually lengthened by how long sperm can survive inside of your reproductive tract (waiting for the egg to be released). So you aren’t just fertile for a day, but for more like 6.

What you may NOT know, is that the sperm can only survive because of a simple fertility sign. One that you can observe from the comfort of your own home (or anywhere else that tickles your fancy). So you can find that window yourself, and through only having unprotected intercourse outside of that fertile time stay baby free with an extremely high efficacy.

I want to talk about that sign (cervical fluid) and the other signs that you can track to know what your fertile window is. These signs will help you form an accurate fertile window even if you have irregular cycles.


What are your fertility signs?

You have three primary fertility signs: Cervical fluid, basal temperature (which means temperature at rest), and cervical position/texture.

These three signs are all influenced by two hormones: estrogen and progesterone. As estrogen levels increase, cervical fluid starts being produced and the cervix softens. Two noticeable changes that tell you you are approaching ovulation and now int hat fertile time.

But why is the increase in estrogen telling you that? Why is that reliable?

Estrogen just so happen to increase before ovulation because the maturing follicle (don’t get freaked out by the word! It’s just the sac around the egg) begins to produce estrogen. And one of the purposes for that estrogen production is so that cervical fluid starts being produced. Why? Because cervical fluid is actually what keeps sperm alive inside your reproductive tract until the egg is released (as I mentioned above).

Now what about progesterone? Progesterone increases after ovulation. That same follicle that matured the egg gets turned into something called the corpus luteum by another hormone that is at play during ovulation. The increased progesterone levels are needed to mature the uterine lining (making it a ripe environment for a possible implantation) and to warm the body up, among other things.

Did you catch the second part? The body is warmed by this hormone that kicks in production after ovulation. That’s why temperature is used as a fertility sign. We know that a temperature increase happens at or soon after ovulation.

Not only that, but progesterone dries up cervical fluid, which serves as a second indicator that ovulation has already passes.

Amazing, innit?


You may be wondering what else changes in your body while your hormones levels are fluctuating.

The answer is: A lot. Some things are reliable changes that every woman will have (and they may be used in other fertility detection devices) and some vary from individual to individual. Some other signs you might see?

Signs that are “definites” but generally not good for birth control:

  • Ferning patterns in saliva or cervical fluid – This happens because of increased estrogen levels, but often won’t happen until after your fertile window would have opened via cervical fluid. Sometimes you will see microscopes like the fertile focus that are meant to lick and view for a ferning pattern, but it’s better to check your cervical fluid if you want the info for birth control.
  • Luetinizing hormone spikes – You can see these with ovulation test strips. Definitely do NOT use these for birth control. They are made for trying to conceive. Everyone gets an LH spike at ovulation, but the strips are limited in what they can measure, so some people won’t see the strip test positive or it will be positive for far longer than it should be.

Some other goodies you might see or notice:

  • Skin changes – Do you feel absolutely glowing at some times in your cycle? Hate other times? Thank your hormones!
  • Sex drive – Generally it’s higher while fertile.
  • Sense of smell and taste – Yes, it changes! For some people it’s subtle, others more pronounced.
  • The way you smell – You’ve got them pheromones goin’ on.
  • Breast changes – Fuller, more tender… This can vary depending on your cycle phase.
  • Appetite – Your metabolism changes during various points in your cycle.

This is just a little sample of all of the things your hormones can do.

Remember, though, with just two of the signs that our bodies give us you can learn how to interpret and apply them to use an effective natural birth control method. And that is due to the fact that these two signs reliable happen before and at ovulation AND because they are needed for fertility (as in the case of sperm only surviving with the help of the cervical fluid).

What changes do you noticed throughout your cycle? Have you ever noticed cervical fluid but weren’t aware of it’s purpose (sometimes you will notice it as a slick sensation while wiping)?




  1. Kristin Johnson says:

    Thanks for this crash course in body awareness that I wish I’d had years ago in order to appreciate the workings of the female body. Your explanation makes a lot of sense and helps differentiate this “window” from other parts of the menstrual cycle. I’m still learning about charting and not sure I’m doing it correctly, but trial and error are a part of learning (while being safe and careful at the same time.)

    • Haha, Kristin, thanks for your comment and thanks for adding in that last bit ;) When someone mentions trial and error when it comes to using this for birth control my heart skips a beat in the bad way! Glad you are playing it safe.

      If you are finding yourself confused check out my program I’ll be re-opening within the week. I found getting the advice of an instructor invaluable when I was learning this stuff! You can sign up to be notified when it’s out here: http://holistichormonalhealth.com/learn/

  2. This is really great, thank you Hannah! I had no idea that our bodies had such reliable signs of ovulation. I’m definitely appreciating the amazing wonder that is my body the more I read your site and learn about this type of birth control.

  3. Thanks. I enjoyed this