Reviewed by

Morgane Leten - Nutrition & Fertility Coach

  • Fertility
  • Hormones

How to Calculate Your Menstrual Cycle

At Guud Woman, we tell everyone about the importance of tracking their cycle. When we first started talking to women about their cycle, we were shocked to learn how many women were completely in the dark. Understanding your cycle and knowing when you ovulate can be so important, and not just when you want to get pregnant! Tracking your menstrual cycle and knowing how to calculate ovulation can unlock so much information about your mood, energy levels, sleep patterns and more. 

If you are trying to get pregnant, calculating your optimal fertility window is key and to do this, you’ll need to track your menstrual cycle. 

In this post, we’ll teach you how to do this using a calendar, your body temperature and your cervical mucus. 

Guud to know: Here’s what your cervical mucus can tell you about your cycle! 

Understanding your menstrual cycle

Put simply, your menstrual cycle begins on the first day of your period (the day you start bleeding) and starts over when your next period begins. A typical menstrual cycle is 28 days, but the normal range is pretty big: anywhere from 22-40 days is considered normal. 

If you’re trying to get pregnant, it’s important to use some sort of menstrual cycle calculator. This could be as simple as writing down the day your period begins on a piece of paper or in your calendar. Or you could use an app that allows you to record other data like symptoms. (Here’s our top period tracking apps, by the way) 

Many changes happen in your body during your cycle, including big changes in hormone levels. About halfway through your cycle, one of your ovaries releases a mature egg. The egg then goes to one of your fallopian tubes where it waits to be fertilized by sperm. At this point in your cycle, the lining of your uterus gets thicker too, which helps a fertilized egg to implant. 

If the egg is not fertilized, that lining sheds, and that’s when you get your period.  

How to know when you are ovulating

If you’re trying to conceive, knowing when you ovulate is very important. You can do this by tracking your cycle, which will help determine your fertile window. While it’s not a guarantee of pregnancy, it is the best time to try and get pregnant. 

And, if you’re not trying to get pregnant, this is equally important to know! Remember: even if you’re absolutely sure about your fertile window, you still need to be careful if you want to avoid pregnancy. You need to take into account that sperm can live 2-5 days and the lifespan of an egg is about 24 hours. 

There are different methods to know when you’re ovulating: the calendar method, the cervical mucus method and basal body temperature method. 

Using the calendar method

This is the low-tech, pen-and-paper method! Each month, mark the first day of your period on a calendar or a period-tracking app (like the ones listed here). The number of days between the first day of your period and the start of the next one is the length of your menstrual cycle. It’s important to note that this may fluctuate each month, but it should be roughly the same each time. If your periods are irregular, then the menstrual cycle calendar method for tracking your cycle won’t be accurate for you. (Also, consider getting in touch with our team. You can support your cycle and hormonal activity by adding the right vitamins and minerals to your diet.)

So, how many days after your period do you ovulate? The answer is about 12-14 days before the start of your new menstrual cycle. Your fertile window is the five days leading up to ovulation, plus the day of ovulation and the day after ovulation. It’s about seven days in total. 

Can I menstruate without ovulating? 

Technically no, but you will still deal with bleeding. Here’s what’s happening: menstruation happens when an egg is released from your ovary that isn’t fertilized. As a result, the uterus sheds its lining and that’s what causes you to bleed. So if you’re not releasing an egg, technically, you cannot menstruate. However, you can still have a period because the endometrium, aka the lining of your uterus, will still shed even if you don’t ovulate. This is what causes bleeding. Instead of menstruation, this bleeding is sometimes referred to as withdrawal bleeding. 

Using the cervical mucus method

Your hormones change throughout your cycle, and one of the things they impact is the amount and consistency of your vaginal mucus! While this may not be for everyone, you can learn a lot if you feel and look at your vaginal mucus each day and record the results on a chart. When you ovulate, the mucus is heavy, wet and slippery. It will have the consistency of raw egg whites. When your cervical mucus looks like this, you are in your most fertile days! This is the best time to try to get pregnant. 

Try tracking your mucus for one cycle and see what you think. It may be tricky at first to know what to look for, but eventually, you’ll notice patterns. You can also take a look at our blog post here with lots more detail on your cervical mucus! 

Using the basal body temperature method

This method is a little bit more involved. To track ovulation through basal body temperature, you need to take your temperature each morning as soon as you wake up (before you even get out of bed!) You need a basal body thermometer, which is a more sensitive version of a regular thermometer. It can measure your body temperature to a tenth of a degree. This is important because a woman’s basal body temperature goes up slightly when she ovulates! Before ovulation, a woman's BBT averages between 36.1°C and 36.4°C.  After ovulation, it rises to 36.4°C  to 37°C. So, if you are diligently tracking your basal body temperature, you will see a rise in your temperature leading up to ovulation. 

You can track your temperature every day on a regular piece of paper, or you can use an app like Natural Cycles. This is the app that Guud founder Morgane uses and it is the first fertility awareness app that comes with a basal thermometer. After three months of tracking, you should have a pretty good idea of when you’re ovulating. 

One important thing to note is that this method is not great at predicting your ovulation when you’re trying to conceive. Once you’ve detected a rise in temperature, you’ve already ovulated. Instead, you use this method to monitor your overall cycle and fertile window. 

What is the most accurate way to track your cycle? 

The most accurate way to track your cycle is to use both the cervical mucus and basal temperature method. Have you heard of the  Sensiplan method? It’s a combination of body awareness and fertility monitoring. The basic idea is that when you are completely aware of the regular signs in your own body, in combination with your basal body temperature, cervical mucus, your bleeding pattern and other symptoms, you will be able to accurately plan for or avoid a pregnancy. 

If you need help tracking your cycle, we recommend that you contact a Sensiplan coach like  Rebecca Verhofstede from Vrouw & Vruchtbaarheid or Bloodywoman. 

You can find out more about Sensiplan here

When to have sex when trying to get pregnant

It would be easy for us to start this paragraph with some sassy comments about the joys of having sex every day. However, at Guud Woman, we know that trying to conceive can sometimes be pretty unsexy. The guud news is that you’re likely to feel more like having sex when you’re ovulating. This is nature’s handy way of helping the world procreate! 

For the best chances of getting pregnant, you should have sex every day, or every other day during the five days leading up to ovulation, the day of ovulation and the day after ovulation. 

There’s lots of gossip about the “right” way to have sex to increase your chance of conceiving. But the science shows that there is no specific sex position that increases your odds of getting pregnant (sorry!). In fact, some lubricants may negatively affect sperm and prevent them from reaching the egg so make sure you’re using a fertility friendly lube. So be aware! 

Want to know more? Here’s how your cycle affects your sex drive. 

What to do if you have irregular periods

If your periods are irregular, get in touch. We can help you! It could be as simple as making some small adjustments to your lifestyle to get you back to a normal period cycle. 

To help maintain a healthy menstrual cycle, there are a few important nutrients that you need:

  • Vitamin B6: Vitamin B6 contributes to normal psychological function which can be useful when suffering from mood swings. But most important is that this vitamin contributes to the regulation of hormonal activity. 
  • Magnesium: This mineral has wide-ranging benefits and that is why we believe at Guud Woman it’s a girl's best friend.  Why we love this powerful mineral so much is because Magnesium contributes to a reduction of tiredness and fatigue.
  • Omega-3 fatty acids: Some studies have revealed that the DHA found in omega-3 can reduce inflammation. Which can be useful when you know that you might have more inflammation in your body the days before your period because of hormonal changes. 

Still have questions about how to calculate your menstrual cycle? Get in touch. We can help!