What is a normal menstrual cycle?

normal menstrual cycle

Sometimes, it can feel like our menstrual cycle has a mind of its own. There’s nothing worse than being surprised by your period, unexplained mood swings, or an unexpected acne breakout. To combat this, we find it helpful to get to know our cycles by keeping track of when we get our periods and when we ovulate. 

What does menstrual cycle length mean?

The menstrual cycle refers to the monthly changes your body goes through to prepare for the possibility of pregnancy. The menstrual cycle starts with the first day of your period and ends when the next period begins, but it is so much more than just your period. An entire menstrual cycle usually lasts between 24 and 38 days, but the length may vary from cycle to cycle, year to year, and person to person. 

Your menstrual cycle involves much more than just your period. In fact, it comprises four different phases, each bringing with it fun (and sometimes not-so-fun) hormonal changes and symptoms. 



  • This is what happens in your body: The first day of your period is the start of your menstrual cycle. If you didn’t get pregnant last cycle, the uterus does not need to keep its lining so it breaks down and sheds galore. That’s right, menstrual blood is a combination of blood and tissue from the uterus.
  • This is how it might affect you: You may feel low on energy and have cramps. We’ve all been there…heating pads and drinking water help ease the pain!

Follicular phase:

  • This is what happens in your body: After the last day of your period, your body preps for ovulation. One of your eggs in the ovaries becomes “mature” aka is ready for fertilization with sperm. The lining of your uterus thickens again getting ready for a possible pregnancy or to flow out of the vagina (and start the next cycle).
  • This is how it might affect you: Your estrogen levels start to rise and you might find yourself being in a better mood and having more energy. 


  • This is what happens in your body: The mature egg is released into the fallopian tube and travels to the uterus. The egg hangs out in the uterus for 24 hours. If it comes in contact with sperm, it is fertilized, if it doesn’t then it dissolves. In other words, people normally talk about ovulation in terms of planning sex for the most likely time to get pregnant.
  • This is how it might affect you: You might feel a boost of energy and inspiration. You’ll experience an increased sex drive! Read more about this in our article on how your cycle affects sex drive.

Luteal phase:

  • This is what happens in your body: The lining of your uterus prepares for a fertilized egg. If the egg is not fertilized, your body releases hormones that start to break down the thick uterus lining that has built up. When the blood and tissue from the uterus flow out, menstruation begins and so does a new cycle.
  • This is how it might affect you: You might feel moodier during this phase. You might also feel easily irritated, experience some sadness, or feel anxious. Your breasts might feel more sensitive or even sore. 


How long is the average menstrual cycle

Everyone’s cycle is different. Chances are, your period doesn’t show up on the same day at the same time every month — and that’s okay! According to the American College of Obstetricians and Gynecologists, this means a cycle that ranges from 24 to 38 days, with bleeding on your period lasting up to 8 days. 

As we mentioned above, there are four phases within the menstrual cycle: the menstruation phase, follicular phase, ovulation phase, and luteal phase. The menstruation phase starts on the first day of your period and ends on the last. Healthy periods typically last around three to seven days. Once your period is over, you enter the follicular phase in which your body prepares to release a mature egg. The length of the follicular phase can range from 10-16 days. 

Following the follicular phase is ovulation, which is when the ovaries release a mature egg in preparation to get pregnant. You’re most likely to get pregnant during the ovulation phase, lasting only 12-24 hours. Finally, during the luteal phase, your body prepares for your next period. This typically lasts for 14 days.

If you miss three or more periods in a year, get your period for more than 7 days, or get your period less often than every 35 days you should consider going to a doctor. This might mean you have an irregular period. Irregular periods are very common and can be caused by several things, including switching birth control, stress, PCOS, pregnancy, and breastfeeding. 

Normal period cycle length when you are on birth control

Birth control methods such as the pill, patch, vaginal ring, shot and IUD can all impact your menstrual bleeding. Many forms of birth control use progestin and/or estrogen hormones to prevent ovulation.

Some birth control methods can increase bleeding, and some can decrease it or even take it away. Periods can be longer, shorter, heavier, or lighter, depending on the method of birth control. Spotting or irregular bleeding are common side effects of hormonal birth control, especially in the beginning stages. 

Many women notice changes in their period after pregnancy postpartum. Your period might take some time to come back or you might bleed more than usual. Either way, it will probably take some time for your cycle to return to normal.

How to calculate menstrual cycle

Menstrual cycles are not always clockwork, so you might wonder: how exactly am I supposed to know if I am menstruating or ovulating?

  • Clue identifies unique patterns in menstrual cycles. This free app uses an algorithm to track your mood, health, and of course, period. The best part? It’s inclusive for all ages and helps you feel in control of your health. Additionally, Clue can link up to any Apple watch (talk about convenience). “The more you use it, the smarter it gets.”
  • Flo is another great option for tracking your period. This free, AI-powered app predicts menstrual cycles, ovulation, and fertile days. Unlike other options, Flo takes into consideration things like PMS symptoms, mood, and sexual activity.
  • Winx Health (formerly known as Stix) ovulation tests help to best understand when you are ovulating. Ovulation tests detect high levels of LH (luteinizing hormone) in your urine, which surge 24-48 hours before you ovulate. Your LH signals to your ovary to release an egg. When an ovulation test detects a surge, it will display a positive result. This means that ovulation will likely happen in the next 24-48 hours, and you will be most fertile in that window. Ovulation only lasts between 12 and 24 hours (that’s how long the egg released from the ovary is viable), so knowing your ovulation day is key to understanding when you can and cannot get pregnant in your menstrual cycle. 

Truly understanding your cycle takes some time. Be gentle with yourself. Once you’ve got a good understanding of your cycle, you can plan your life accordingly, which is incredibly empowering and will make things so much easier. For more like this, head to the Winx Health Real Talk blog or send your questions to hi@hellowinx.com.

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