Reproductive Health

Understanding Your Menstrual Cycle

2 min read

What is a menstrual cycle?

A menstrual cycle is the name for the changes your body experiences once per month to prepare for pregnancy. If you are not pregnant that month, you’ll typically get a menstrual period instead. This cycle is driven by changes in hormones coming from your ovaries. 

There are several steps that the body takes to prepare for pregnancy:

  1. The eggs in your ovaries begin to mature until they are ready to be fertilized by a sperm. 
  2. The lining of your uterus becomes thicker with more tissue and blood, so that an egg can grow there if needed. 
  3. You ovulate, meaning you release an egg from your ovary and it travels to your uterus. 


If your body determines it is not pregnant, it takes all of the extra tissue and blood and releases it through your vagina, which is how you get your period

What is the normal length of time for menstrual cycles?

A menstrual cycle starts the first day of your period and ends when the next period starts. Every person’s cycle may be a little different, but typically menstruation happens every 21-35 days and lasts 2-7 days. Certain birth control methods may affect your menstrual cycle or stop it altogether. For example, the Depo shot and IUD are typically associated with light or non-existent periods.

Fun fact: Twentyeight Health got its name because 28 days is the average length of a person’s menstrual cycle! 

Do menstrual cycles change?

Some people have very predictable cycles and other people have irregular cycles, making it difficult to know when a period will come. It’s usually fine for someone to have irregular cycles, especially when you’re young, but you should speak with your doctor if you notice any significant changes, heavy bleeding, or other concerning symptoms. For some people, birth control pills can help regulate cycles.

As you age, your menstrual cycle will stop and you will enter a stage called menopause. When your body isn’t able to support pregnancy anymore, it stops the menstrual cycle altogether. The transition to menopause typically happens between age 45-55

Do I need to track my menstrual cycle? 

It can be helpful to keep track of your menstrual cycle so that you are aware of any significant changes happening in your body. For instance, if you know you missed a period, you may decide to take a pregnancy test. If you are experiencing health issues and go see a doctor, they will likely ask you when your last period started. 

When can I get pregnant during my menstrual cycle?

Tracking your cycle can be especially helpful if you’re trying to get pregnant, so that you know when you have the highest chance of conceiving. There are many cycles tracking apps available. The best timing to have sex is the 3-4 days leading up to ovulation, which is known as your fertile window. You can read more on our How to Get Pregnant Guide


Looking for more personalized info? Message a doctor through Twentyeight to get medical advice based on your needs and lifestyle.

With the participation of
Dr. Eddie Garcia

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