The Importance of Knowing Your Menstrual Cycle

Your menstrual cycle is how your body prepares for a potential pregnancy. It usually lasts around 28 days, but it can range anywhere from 21 to 35 days. During this time, your hormone levels fluctuate, causing various changes throughout the body1.

Many women track their menstrual cycle so that they know when their period is coming. This can help women to prepare for their period and avoid the unexpected. While predicting your period is a major benefit to tracking your cycle, there are several other advantages to understanding your menstrual cycle.

Knowing your menstrual cycle can provide key insights into your overall health and wellbeing. For example, it can help you to know when you are ovulating, to understand fluctuations in sex drive, or to identify when something may be off in your body. This article will discuss the details of these benefits to understanding your cycle.

Knowing when you ovulate

In a woman of reproductive potential’s body, ovulation is an event that occurs every month. During ovulation, the ovary releases an egg into the fallopian tube where it can be fertilized2. After that, the egg can stay in the fallopian tube for up to 24 hours. Ovulation is essential to getting pregnant.
Tracking your menstrual cycle can tell you when you are ovulating and when your fertility window occurs. The fertility window is a period of time in which you have the greatest chances of conceiving. The fertility window occurs around your ovulation date. Typically, it includes the five days prior to ovulation, the ovulation day, and the day following ovulation1.
Knowing when you ovulate and your fertility window can be useful information. Depending on your goals, this data can help you to increase or decrease your likelihood of conceiving. For example, if you would like to get pregnant, having sex during the fertility window can optimize your chances of conceiving. If you are avoiding pregnancy, you would likely want to refrain from having unprotected sex during your fertility window1.

Knowing when something is off

Most women have periods lasting between four to seven days and a cycle that is between 21 to 35 days. When tracking your menstrual cycle, you can also include key information such as the heaviness of your flow and your symptoms. By keeping a log of your menstruation patterns, you can more easily identify what is considered “normal” for your body.

Likewise, knowing your period patterns makes it easier to identify when your period is irregular. Period irregularities can include:

  • Periods that happen greater than 35 days apart or less than 21 days apart
  • Periods that occur with abnormal nausea, vomiting, pain, or cramping
  • Periods that are abnormally light or heavy
  • Periods that last more than seven days
  • Missing multiple periods in a row
  • Bleeding in between periods

Several health conditions and lifestyle changes can cause period irregularities. For example, stress, weight, diet, and exercise can all influence aspects of your menstrual cycle. Other times, something more serious could be causing abnormalities. Conditions that can affect your cycle include:

  • Endometriosis
  • Uterine polyps and fibroids
  • Polycystic ovary syndrome (PCOS)
  • Premature ovarian insufficiency
  • Pelvic inflammatory disease
  • Cancer
  • Pregnancy complications3

These conditions can be serious and often require medical attention. Thus, tracking your cycle can help to identify irregularities so that you can address a potential problem early.

Understanding your sex drive

Most women do not have a consistent libido throughout the course of their menstrual cycle, usually due to hormone fluctuations. Hormones that affect a woman’s sex drive include estrogen and progesterone, amongst others4.

High estrogen levels increase sex drive and promote vaginal lubrication. In contrast, high progesterone levels can decrease libido. Likewise, the changes to these hormone levels throughout your cycle can influence your desire for sex. For example, many women have increased libido before and during ovulation when estrogen levels are high5.

Understanding and managing mood changes

Many women are familiar with the potential for mood changes during or around their period. In fact, 75 percent of women experience premenstrual syndrome, commonly known as PMS. Symptoms of PMS can usually be attributed to changes to hormone levels during one’s cycle.

PMS can include symptoms such as irritability, anxiety, depression, fatigue, impulsiveness, or lethargy. Usually, the symptoms subside within a few days following menstruation.

Knowing your menstrual cycle can help you to identify what mood changes you experience throughout your cycle and when they happen. Knowing this information can help you to prepare for these changes6.


Your menstrual cycle can be a key indicator of your overall health and wellbeing. Whether your goal is to get pregnant or just have a better understanding of your mood and libido, tracking your periods can be useful. To better understand your cycle, consider tracking your periods and using an app.

  1. Calculating your monthly fertility window. (2022, March 10).
  2. Holesh, J. E., Bass, A. N., & Lord, M. (2022). Physiology, ovulation. In StatPearls. StatPearls Publishing.
  3. Abnormal menstruation (Periods): Types, causes & treatment. (n.d.). Cleveland Clinic. Retrieved July 10, 2022, from
  4. Cappelletti, M., & Wallen, K. (2016). Increasing women’s sexual desire: The comparative effectiveness of estrogens and androgens. Hormones and Behavior, 78, 178–193.
  5. Female sex hormones: Types, roles, and effect on arousal. (2019, April 5).
  6. Hoyer, J., Burmann, I., Kieseler, M.-L., Vollrath, F., Hellrung, L., Arelin, K., Roggenhofer, E., Villringer, A., & Sacher, J. (2013). Menstrual cycle phase modulates emotional conflict processing in women with and without premenstrual syndrome (Pms) – a pilot study. PLoS ONE, 8(4), e59780.