Why You Might Have 2 Periods in One Month

Getting two periods in one month is most often due to something simple and harmless. It some cases, though, it could indicate an underlying health problem that requires treatment.

Possible reasons you may have two periods in one month include:

• Age
• Skipping or stopping birth control
• Lifestyle or habit changes
• Weight gain or obesity
• Endometriosis
• Thyroid disease
• Uterine polyps or fibroids
• Pelvic inflammatory disease
• Cancer

This is not an uncommon occurrence. For some, two periods a month may even be their norm. But having frequent periods consistently should always be evaluated by a healthcare provider.

This article explores these possible reasons for having two periods in one month, plus the signs and symptoms of conditions that can cause irregular menstrual cycles and how they're treated.

Age and Frequent Periods

Period frequency, how many days it lasts, and how much you bleed are all influenced by your body’s hormone levels. These levels fluctuate throughout your life.

During your teen years, cycles are often irregular because of all the hormone changes that are taking place.

Your cycles may normalize in your 20s or 30s only to once again become irregular in your 40s and early 50s as you make the transition to menopause.

Hormonal Changes	Average Age	Age Range
First period	12	8-16
Perimenopause	41-43	Late 30s-mid-40s
Menopause	51	Late 40s-early 50s
Early menopause	--	40-45
Premature menopause	--	Under 40

Teen Years

The average age to start menstruating is 12, but that’s not a rule. Your first period can come anywhere between 8 and 16.

For the first few years, your periods might be irregular because of constantly shifting hormones. These shifts may cause frequent periods such as two periods in one month.

These early fluctuations are usually not a cause for concern. However, if you don't get more regular over time, talk to a healthcare provider.

If there’s no underlying condition causing frequent or irregular periods, providers may prescribe oral contraceptives (birth control pills) to regulate your cycle.

Perimenopause

Perimenopause is when you are transitioning to but have not yet reached menopause. (Menopause begins when you haven't had a period for 12 months in a row.)

During this time, your estrogen levels drop. That can make your cycle irregular and your periods more (or less) frequent—possibly causing two periods in one month.

The blood flow may also be shorter or longer, lighter or heavier.

Most people with female reproductive organs start this phase between their late 30s and mid-40s. The process generally lasts for about eight to 10 years before menopause begins.

Some people have early (before age 45) or premature (before age 40) menopause. Changes in period frequency can be a sign that you’re entering one of these phases.

If period changes are related to perimenopause, you might be able to regulate them with birth control pills, patches, or rings.

Skipping or Stopping Birth Control

Oral contraception (birth control pills) suppresses your normal menstrual cycle with hormones that keep your body from ovulating.

Birth control pills usually come with a three-week supply of pills with hormones followed by a week of pills without any hormones (placebos). The lack of hormones during the placebo week triggers your period.

The same thing can happen when you go off of the pill or even miss just a pill or two. This can happen even if you've had a recent period, leading to two periods in one month.

Your body can also react this way if you make a mistake with another form of hormonal birth control like the birth control patch or the ring.

The right way to restart birth control after missing one or more doses depends on the type. Always read the information that comes with your pills. You can also ask your provider or pharmacist what to do if you forget a pill.

Lifestyle Changes

Changes in your day-to-day routine can affect your menstrual cycle. Certain habits and situations might make you have two periods in one month or get your period early.

Lifestyle factors that can change your menstrual cycle include:

• Stressful events
• Extensive travel
• Exercising more
• Lack of sleep

All of these factors put your body under stress, which throws off the hypothalamus and leads to the release of excess stress hormone (cortisol).

All that extra cortisol changes your body’s ability to regulate hormones, which can lead to irregular menstrual cycles and either more or fewer periods.

Typically, getting back to your normal routine will also get your cycle back on track.

Weight Gain or Obesity

Rapid weight gain can throw your cycle. That's because it affects the part of your brain that regulates hormones (the hypothalamus).

That can lead to hormonal fluctuations that may cause two periods in one month or to infrequent periods.

Obesity has a complex relationship with menstruation. High levels of fat (adipose tissue) can upset the balance of sex hormones and lead to excess estrogen.

Too much estrogen can make you have short menstrual cycles and more periods.

Hormonal imbalances can also cause heavier bleeding, more cramps, and longer-lasting pain during your period.

Menstrual changes related to weight are most severe when the extra fat is mostly around the belly.

Endometriosis

Endometriosis is a medical condition that causes tissue that's similar to the endometrium to grow in other parts of the body.

The main symptoms of endometriosis are painful periods, excessive bleeding, and short menstrual cycles—which could mean having two periods in one month.

People with endometriosis have extra and more severe periods in part because the endometrium has overgrown, which means there’s more of it to be shed.

If you have endometriosis, you might also have bleeding and pain when you ovulate because the tissue can stick to the ovaries and form cysts.

Other symptoms of endometriosis include:

• Menstrual cramps that do not get better relieved by over-the-counter anti-inflammatory drugs
• Nausea and vomiting
• Excessive gas
• Diarrhea
• Chronic pelvic pain
• Fatigue
• Headaches or migraines
• Leg pain
• Pain during vaginal penetration
• Painful bowel movements
• Difficulty getting pregnant

Endometriosis can sometimes be managed with low-dose birth control pills or other hormone therapies.

Surgery to remove the lesions may help, but the tissue often comes back. Some people with endometriosis have their uterus and/or ovaries removed (hysterectomy and oophorectomy).

Thyroid Disease

Your thyroid gland and the hormones it makes are important for regulating your menstrual cycle.

When you don't have enough thyroid hormone (hypothyroidism), your periods can be really heavy or more frequent, such as two periods in a month.

You may need to change your pad, tampon, or cup every hour or double up your protection (such as wearing a tampon and pad). Your periods may also last longer than a week.

Other symptoms of hypothyroidism include:

• Feeling very cold
• Constipation
• Muscle weakness
• Unexplained weight gain
• Joint or muscle pain
• Fatigue
• Dry skin
• Thinning hair
• Feeling depressed or sad
• Puffy face
• Sweating less than usual

Treatment with human-made (synthetic) versions of thyroid hormones should help regulate your menstrual cycle.

Uterine Polyps or Fibroids

Uterine polyps (also called endometrial polyps) are soft growths in the endometrium. They can be as small as a sesame seed or larger than a golf ball.

You can have one or multiple polyps, which are usually not cancerous. They're more common with age and rare in people under 20.

Symptoms of uterine polyps include:

• Post-menopausal bleeding or spotting
• Bleeding after vaginal penetration
• Infertility

Uterine fibroids are growths in the muscle tissue rather than the endometrium. They're also called leiomyomas, myomas, or fibromas.

Fibroids can be inside or outside the uterus. As with polyps, you can have one or several.

Symptoms of uterine fibroids include:

• Bloating and swelling in the abdomen
• Frequent urination and being unable to empty your bladder
• Pain during vaginal penetration
• Lower back pain
• Constipation
• Vaginal discharge

Both polyps and fibroids can cause problems with your menstrual cycle. You may have more frequent periods (including two periods in one month), longer and heavier periods, and bleeding between periods.

The treatment for polyps and fibroids ranges from symptom management and hormonal therapies to surgical removal of the growths. In more serious cases, people need to have a hysterectomy.

Pelvic Inflammatory Disease

Pelvic inflammatory disease (PID) is an infectious illness. It occurs when normal vaginal bacteria or sexually transmitted infections (STIs)—especially chlamydia and gonorrhea—move from the vagina up to the:

• Uterus
• Fallopian tubes
• Ovaries

The risk of PID is higher when:

• You're on your period
• Your cervix is open due to recently having a baby, miscarriage, abortion, or IUD placement)

PID can cause irregular menstrual cycles, including two periods in one month, or spotting and cramping between periods.

Other symptoms of PID include:

• Pain or tenderness in the lower abdomen
• Yellow or green vaginal discharge with a strange odor
• Fever or chills
• Nausea and vomiting
• Burning with urination
• Pain during vaginal penetration

Repeated bouts of PID can cause scarring on the fallopian tubes that can lead to chronic pelvic pain, ectopic pregnancy, and infertility.

Cancer

It’s not as common as other reasons, but menstrual changes (including two periods in one month) can sometimes be a sign of cancer.

Cancers of the reproductive organs, including the uterus, cervix, and ovaries, can change your hormones and menstrual cycle.

Uterine cancer can cause you to have periods more often. Cervical and ovarian cancers are more often associated with long and heavy periods rather than more frequent periods.

Uterine Cancer

Two types of cancer are possible in your uterus:

• Endometrial cancer: Tumors develop in the uterine lining (by far the most common type)
• Uterine sarcoma: Cancer develops in the wall of the uterus (extremely rare)

Either type of cancer can cause more frequent periods that might also be very long and heavy—especially if you’re over the age of 40.

These cancers can also cause bleeding between periods and spotting or bleeding after menopause.

Other symptoms of reproductive cancers include:

• Pain or cramping in the lower abdomen/pelvis
• Unexplained weight loss
• Thin, clear, or white vaginal discharge after menopause

The treatment for uterine cancer depends on the type you have and how healthy you are. A few options include:

• Chemotherapy
• Radiation
• Hormone therapy
• Immunotherapy
• Medications that stop cancer cells from multiplying
• Surgery (hysterectomy)
  

When to Call Your Provider

While some of the causes of frequent periods are not serious and don't need treatment, don’t assume that’s the case if you have two periods in one month.

Call your provider if:

• Your period becomes irregular, especially if it’s sudden or without an obvious cause (like a missed birth control pill)
• Your periods are less than 21 days apart
  
• You have a period that lasts more than seven days
  
• You have an unusually heavy or painful period
• You bleed between periods
• You bleed at all after menopause

By doing so, you may catch a problem early and start the treatment you need. If there's not a problem, your provider can put your mind at ease and help figure out what you need to do to get your cycle back on track.

Summary

Shorter menstrual cycles are not necessarily a sign that something is wrong. For some people, they’re normal. However, if you're usually regular and suddenly have two periods in one month—and the cause isn't obvious—talk to your provider.

Many things can make your period come more often than usual. Natural hormone fluctuations can cause this, as can missing a birth control pill and lifestyle factors like being overweight or stressed.

Having your period twice in one month could also be a sign of a medical condition that needs treatment.