Why Did I Get My Period Twice a Month? 11+ Causes Explained by Experts

Experiencing your period twice in one month can be confusing and concerning. While a typical menstrual cycle lasts about 28 days, anything between 21 and 35 days is considered normal. If your cycle is on the shorter end, you might naturally have two periods in some calendar months.

However, if this is a new change for you, it's important to understand the potential causes. This comprehensive guide synthesizes information from leading health experts to help you understand why you might be bleeding more frequently and when it's time to consult a doctor.

Is It a Second Period or Spotting?

First, it's crucial to distinguish between a true second menstrual period and intermenstrual bleeding, also known as spotting. They aren't the same, and identifying which one you're experiencing can help narrow down the cause.

A true second period, a condition sometimes called polymenorrhea, means you are having a full menstrual cycle more frequently than every 21 days. Spotting is lighter bleeding that occurs between your regular periods.

Here’s a quick comparison:

Feature	Menstrual Period	Intermenstrual Bleeding (Spotting)
Flow	Heavier; requires pads, tampons, or a menstrual cup.	Very light; may only be noticeable on toilet paper or as a few spots in your underwear.
Duration	Lasts for several days (typically 3 to 7).	Usually brief, lasting only a day or two.
Color	Bright red, but can be dark brown at the beginning or end.	Often pinkish or dark brown.
Symptoms	May be accompanied by cramps, bloating, and breast tenderness.	Typically occurs without other menstrual symptoms.

Understanding this difference is the first step. If you're experiencing full, heavy bleeding, it's more likely a true period. If it's light and brief, it's probably spotting. Both warrant attention if they are a new or persistent issue.

Common Reasons for Getting Your Period Twice a Month

Numerous factors, from natural life stages to underlying medical conditions, can cause frequent bleeding.

Natural Cycle Variations & Life Stages

Your body goes through significant hormonal shifts at different points in your life, which can directly impact your cycle's regularity.

• Puberty: In the first few years after menstruation begins, it's very common for cycles to be irregular. Hormones are still stabilizing, which can lead to shorter or longer cycles, sometimes resulting in two periods in one month. According to the Office on Women's Health, it can take up to 3 years for a young person's cycle to become regular.
• Perimenopause: This is the transitional period before menopause, typically starting in a person's late 30s or 40s. As estrogen levels fluctuate and decline, periods can become more frequent and irregular before they eventually stop.
• Naturally Short Cycles: Some individuals simply have a shorter menstrual cycle. If your cycle is consistently 21-24 days long, it's mathematically possible and normal for you to have a period at the beginning of a month and another at the end.

Lifestyle and Environmental Factors

Sometimes, the cause of a menstrual irregularity isn't an underlying condition but a response to external stressors.

• High Stress: Emotional or physical stress can disrupt the balance of hormones that regulate your menstrual cycle. The stress hormone, cortisol, can interfere with your reproductive hormones, potentially leading to an early period.
• Significant Weight Changes: Both rapid weight gain and loss can throw your hormones off balance. Fat tissue (adipose tissue) produces estrogen, so significant changes can alter your hormone levels and affect your cycle's frequency.
• Excessive Exercise: While regular exercise is healthy, intense or excessive physical activity can place stress on the body, leading to hormonal disruptions and irregular periods.

Image Source: Pexels

Hormonal Imbalances and Related Conditions

Persistent frequent bleeding is often linked to an underlying hormonal imbalance or a condition that affects your hormones.

• Thyroid Disorders: Your thyroid gland is a crucial regulator of hormones and metabolism. Both an underactive thyroid (hypothyroidism) and an overactive thyroid (hyperthyroidism) can cause menstrual irregularities, including more frequent periods.
• Polycystic Ovary Syndrome (PCOS): PCOS is a common hormonal disorder characterized by irregular periods, excess androgen (male hormone) levels, and cysts on the ovaries. This hormonal imbalance can cause either infrequent or very frequent periods.

Uterine and Reproductive Health Conditions

Structural issues within the reproductive system can also be a source of abnormal bleeding.

• Uterine Fibroids or Polyps: These are non-cancerous growths that develop in or on the uterus. Both fibroids (in the muscle tissue) and polyps (in the uterine lining) can cause heavy bleeding, prolonged periods, and bleeding between periods, which can feel like a second period.
• Endometriosis: This condition occurs when tissue similar to the lining of the uterus grows outside the uterus. It can cause severe pain, heavy bleeding, and irregular cycles.
• Pelvic Inflammatory Disease (PID): PID is an infection of the reproductive organs, often caused by untreated STIs like chlamydia or gonorrhea. It can cause inflammation and lead to irregular bleeding, cramping between periods, and pain.

Medications and Contraceptives

What you put into your body can have a direct effect on your cycle.

• Hormonal Birth Control: Starting, stopping, or missing doses of hormonal contraceptives (like the pill, patch, or ring) is a very common cause of breakthrough bleeding. Hormonal IUDs can also cause irregular spotting, especially in the first few months.
• Emergency Contraception: The "morning-after pill" contains a high dose of hormones that can disrupt your cycle, sometimes causing an early period or spotting.
• Other Medications: Certain medications, including blood thinners, some NSAIDs, and thyroid medications, can influence your menstrual flow and regularity.

Pregnancy-Related Bleeding

While a period stops during pregnancy, some types of bleeding in early pregnancy can be mistaken for a light or unusual period.

• Implantation Bleeding: This is light spotting that can occur when a fertilized egg attaches to the uterine lining.
• Ectopic Pregnancy: This is a serious, life-threatening condition where a fertilized egg implants outside the uterus, often in a fallopian tube. It can cause vaginal bleeding and sharp abdominal pain and requires immediate medical attention.
• Early Miscarriage: Bleeding can also be a sign of a miscarriage.

How Two Periods a Month Can Affect Fertility

If you are trying to conceive, frequent bleeding can present challenges. Irregular cycles make it difficult to predict your fertile window and track ovulation using calendar-based methods.

Furthermore, some of the underlying causes of frequent periods, such as anovulation (not releasing an egg), PCOS, or thyroid issues, directly impact fertility. The frequent blood loss can also lead to iron-deficiency anemia, which can cause fatigue and is not ideal when trying to achieve a healthy pregnancy.

A diagram of the female reproductive system showing the location of the uterus, ovaries, and fallopian tubes. Image Source: Wikimedia Commons

One-Time Anomaly vs. A Recurring Problem: When to See a Doctor

An occasional irregular cycle due to stress or travel is usually not a cause for alarm. However, if you experience frequent bleeding for two to three consecutive months, or if the bleeding is accompanied by other concerning symptoms, it's time to see a healthcare provider.

Schedule an appointment with your doctor or gynecologist if you experience any of the following:

• Your periods consistently arrive less than 21 days apart.
• You are bleeding so heavily that you soak through a pad or tampon every hour for several hours.
• Your period lasts longer than seven days.
• You are passing blood clots the size of a quarter or larger.
• The bleeding is accompanied by severe pain, dizziness, fatigue, or shortness of breath.
• You experience any bleeding after menopause.
• The pattern is new and persists for more than a couple of cycles.

Your doctor will likely ask about your medical history and menstrual patterns and may perform a pelvic exam. Depending on your symptoms, they may recommend blood tests to check hormone levels, a pregnancy test, or an ultrasound to look for fibroids, polyps, or other abnormalities.

References

• Medical News Today - Two periods in one month: Causes and is it normal
• Verywell Health - Why Did I Get Two Periods in One Month?
• Health.com - Is It Normal To Have Two Periods in One Month?
• Healthline - What Causes Two Periods in One Month?
• USA Fibroid Centers - Two Periods In One Month: What Does It Mean?