Why Do I Get My Period Twice a Month?

For most women, your menstrual cycle will last between 24 and 38 days. (That's counting your cycle length from the first day of this month's bleeding to the first day of your next period. Within that range, most women experience cycles that last 28 days. Of course, there are ranges of cycle length, especially when you're new to menstruation.  But when your cycle length changes suddenly, and you start getting a period twice a month, you can't consider that "normal."

Now, in some cases, getting your period twice in a 30-day period (clinically described as having polymenorrhea) is just a sign that your cycle is on the shorter end of normal. But for other women, this could be a sign of a serious underlying condition. As such, you need to get an accurate answer to the question, “Why did I get my period twice in one month.” For some women, this could be a lesser-known sign of uterine fibroids, which is why we're highlighting this issue during Fibroid Awareness Month. But, for other women, the causes could be something else entirely. So, to help you figure out what’s causing your irregular period, here are four conditions that could cause you to experience more than one monthly menstrual cycle.

Why am I Getting a Period Twice a Month? Uterine Fibroids

Uterine fibroids are non-cancerous tumors that grow in or on your uterus. (There are four main locations where they grow, each being classified by that location. So, you may have a diagnosis of intramural, penduculated, or subserosal fibroids. And, regardless of their classification, any one of these growths can cause several unpleasant symptoms, including painful, heavy periods or bleeding between cycles. For that reason, if you get your period twice a month, but also have pelvic pain, heavy cycles or these other fibroid symptoms, uterine growths could be responsible for getting a period twice in one month.

Period Twice in One Month with Endometriosis

Endometriosis can also cause changes in your menstrual cycle. Sometimes, it’s hard to tell the difference between endometriosis and fibroids, because they cause similar symptoms. But, with endometriosis, your pain develops when uterine tissue forms in other parts of your body. Then, you may notice stomach pain, pelvic pain, heavy periods and bleeding between periods. At that point, it may seem like you’re menstruating more than once a month.

As we mentioned, diagnosing endometriosis is difficult. While your doctor may notice endometrial tissue on an ultrasound, you’ll need a small surgical procedure to get an accurate diagnosis.

Changes in Your Cycle When You're Pre-Menopausal

To say you've entered menopause, you need to have gone one full year without a period. But, in the months or years leading up to menopause, called perimenopause, your cycle goes through many changes. Some months, you may not have a period at all. (Or your flow could be very light.) At other times, your cycle may shorten, so it seems like you’re menstruating more than once in a 30-day period.

Hormonal Fluctuations

When you have thyroid issues, your menstrual cycle may be impacted. After all, the thyroid gland regulates hormone levels in your body. So, if it’s under or overactive, your hormones will fluctuate and your cycle may change soon afterward.

Similarly, if you suddenly gain weight, your cycle may change. And that’s because weight gain can contribute to changes in your estrogen levels, which could alter when and how your period shows up.

Stress and Your Period Changes

As we saw during the COVID-19 pandemic, stress and changes in your sleep cycle impact your menstrual cycle. During that time, many women got their period twice a month—or even more often. Fortunately, when stress is a trigger, your body will usually reset once you can relax or adjust to your new normal.

Recently, we learned of another surprising why the pandemic may have affected women's periods. A study in The British Medical Journal revealed that getting vaccinated for COVID can affect your period timing. Specifically, they learned that women's periods started about one day late, on average, after receiving the first dose of a COVID vaccine. Then, if the women received two doses within one menstrual cycle?

Well, the changes magnified. In this case, women's periods began four days late on average. But 13 percent of the women in the study experienced period delays of eight or more days. Meaning, the following month, those women may have experienced a period twice a month, since the delays appeared to be temporary, and most women's cycles returned to normal after one month. Additionally, many women reported having heavier periods after their COVID vaccines, but this study did not examine that reported effect.

As you can tell, so many things can make your period come twice a month. Sometimes, it’s hard to tell what’s causing the trouble on your own. So, how can you know when to worry?

Here’s the deal: you’re the person who best understands your body. For that reason, any cycle change that seems unusual to you is worth mentioning to your doctor. Are you concerned that fibroids could be the reason you're getting a period twice a month? Reach out to our Dallas area fibroid specialists and ask for a consultation. We’re here to discuss your symptoms and review all your fibroid treatment options.