The menstrual cycle is made up of four phases and 28-35 days that are each unique and bring with them their own ups and downs. Our hormones dictate the release of an egg during ovulation as well as the shedding of the lining of the uterus during our period. And because these hormone levels change during the various stages of our lives, it’s only natural that the monthly bleeding we experience changes, too. 

So, how does your period change with age?

We're diving into this topic and speaking to Dr. Dara Havemann of Dallas IVF to shed light on the expected changes to a woman’s period – and in turn, her fertility – throughout her life. 

Your period in your 20s and 30s 

During your teenage years, a menstrual cycle that lasts 21 to 45 days is considered “normal”. By your 20s, your period tends to be more “predictable” and can last anywhere between 21 to 35 days. In your 30s, your period should continue to be regular, with a healthy flow generally lasting up to 7 days. 

In your 20s and 30s, a menstrual cycle less than 24 days or longer than 38 days may be considered irregular, and it’s important to consult with your healthcare provider to rule out any underlying health conditions. 

According to the CDC, approximately 65% of women of childbearing age use some form of contraceptive, which can also impact the menstrual cycle. 

What happens to your period during perimenopause?

It’s in your early 40s that more significant changes to the menstrual cycle occur, as most women will begin to experience perimenopause between the ages of 40-44. 

Perimenopause occurs when your ovaries start to produce less estrogen and may not consistently release an egg during ovulation. This is often marked by changes in menstrual flow and in the length or duration of your cycle. 

"Period changes associated with age for the average woman will begin in her 40s and become noticeable by her late 40s," says Dr. Dara Havemann of Dallas IVF. “This transition marks the onset of perimenopause, a stage that precedes menopause, during which hormone levels start to fluctuate.” 

Dr. Havemann explains that as you progress through perimenopause, your periods begin to become more frequent – every 2 to 3 weeks – before gradually spacing out. Your flow could also become heavier before it gets lighter and ceases altogether. 

By your 50s, your ovaries have most likely stopped producing estrogen, which means you’ve officially entered the menopause stage. A doctor can confirm this when you haven't had a period for 12 consecutive months, and pregnancy is no longer possible. 

Menstrual cycle concerns to look out for

Be the expert in you.

Take the Quiz

While menstrual changes occur for every woman, everyone’s body and experience are vastly different. Still, Dr. Havemann stresses the importance of vigilance regarding shifts in your period: "Any change in your period from what is normal for you is good to check in with your medical provider to ensure these are all within the normal range," she advises. “These changes could signify various underlying factors, some of which may require medical attention.” 

Further, for those navigating the path to conception, the evolving nature of your period can hold specific implications. Dr. Havemann emphasizes that any shift in your menstrual cycle during attempts to conceive warrants attention. "Any change in your period when trying to conceive is a reason to seek evaluation or consult your fertility provider," she states. “Changes in the frequency and regularity of your cycle can affect your fertility journey.” 

From regular cycles in your 20s and 30s to the ebbs and flows of perimenopause, your period is a dynamic reflection of the stages you experience throughout life and a testament to the incredible journey of womanhood. By staying attuned to your body's signals and seeking professional guidance – especially if you’re hoping to conceive – you can navigate these changes with grace and empowerment, ensuring your well-being at every stage.

While it can be hard to track changes in your cycle, tools like U by Kotex's Period Calculator make it easier by letting you upload the days of the month you're most likely to bleed straight to whatever calendar app you use.