Yes, Your Period Can Change. Here's What To Expect

If you're not wild about your period, then you're in luck. Why? Because it's going to change. Yes! The period you get at this stage in your life isn't going to be the same period you're likely to get a decade from now or even a few years from now — depending on where you are in your menstrual journey.

While for some this may be great news, as they're bogged down with cramps and a heavy period that lasts several days, for others, the thought of a change can evoke an "oy vey."

Although there are several reasons why a period may change, including medical conditions, stress, medications, and other factors, you'll see a shift in your period during your lifetime even without these things (via Edward-Elmhurst Health). From your very first period to your very last, your menstrual cycle is going to have a lot of ups and downs, which makes sense considering the average American woman will have roughly 450 periods before menopause shows up, according to Helping Women Period. If you want to break that number down even further, that's a whopping 3,500 days of menstruating over a lifetime. Yikes.

No matter your age, here's what you can expect your period to do (or not do) over the course of your life.

According to a study published in the scientific journal Pediatrics, the average age at which girls get their first period is 12. From here and into the teenage years, periods tend to be irregular. Because the body isn't considered particularly fertile at this stage, it's not necessary for your period to find its rhythm. It's not until your 20s that your period, even if you're not taking hormonal birth control, finally gets on an even keel, relatively speaking.

"As one gets a little more mature going through the menarche stage, they start ovulating," Mary Jane Minkin, M.D., a clinical professor of OB-GYN and reproductive sciences at Yale School of Medicine, tells Healthline. "When you start ovulating, barring anything abnormal going on, you start having more regular monthly cycles."

With these regular cycles, you also become more aware of your body and possible issues. Painful periods, MIA periods, or abnormally heavy menstrual cycles can give you a heads up that something isn't right, and you should have a doctor check things out.

When your 30s roll around, periods can get a little haywire again — not only because this is a decade in which women tend to have pregnancies but also because perimenopause can start in the mid-to-late 30s. Although perimenopause doesn't start until early-to-mid 40s in most women, according to Mount Sinai, it's not unheard of that a woman in her 30s may experience the very beginning symptoms — the obvious one being a whacky menstrual cycle.

By the time most women reach their 40s, perimenopause is officially underway. While menopause is still a decade down the road, perimenopause can throw a wrench in the most regular of menstrual cycles.

"The thing I always say about perimenopause symptoms is the one thing that's predictable is that nothing is predictable," Lauren Streicher, M.D., a Chicago-based OB-GYN and author of "Sex Rx-Hormones, Health, and Your Best Sex Ever," tells Health.com.

It's also important to keep in mind that although the word "perimenopause" has "menopause" in it, it doesn't mean your ovulating days are over. So, yes, you can still get pregnant. You'll know you've completed menopause when you've gone a full year without a period, according to the Cleveland Clinic. Although there's no definitive time in one's life when this will occur, the average age for women in the U.S. is 51 (via the Mayo Clinic).

Because menopause can take anywhere from seven to 14 years to reach its completion (via the National Institute of Aging), you can expect your period to be just as confusing as it was when you first got it. It will come and go as it pleases, overstay its welcome, and just when you think it's gone for good, make a surprise visit — most likely when you're wearing white. But, at this age, you can take comfort in knowing that your period days are numbered. You've menstruated for 3,500 days of your life, and now all that's behind you.