It is possible to mistake vaginal bleeding for a second period. Unusual vaginal bleeding can be a symptom of a more serious condition, such as:
- endometriosis
- endometrial polyps
- uterine fibroids
This article will discuss possible causes of two periods in the same month, how to tell the difference between a period and vaginal bleeding, and when to contact a doctor about multiple periods or other bleeding.
For some people, it can be normal to have two periods in a month if it happens occasionally. However, it is not normal to consistently have two periods each month.
A typical menstrual cycle can range from 24 to 38 days. Every person is different, though, and your cycle may vary from month to month. You may simply have a shorter menstrual cycle that results in more frequent periods.
Learn more about what happens during a menstrual cycle.
For teenagers who have just started to have periods, it is normal to have irregular menstrual cycles, including having two periods in 1 month. The years leading up to menopause can also include changes in menstrual patterns that increase the frequency of your periods.
However, for people who have gone through menopause, vaginal bleeding is not an expected symptom. Bleeding after menopause may be a sign of a serious condition, including certain types of cancer.
If you are past menopause and experience any type of vaginal bleeding, contact an OB-GYN.
Many factors may lead you to have two periods in 1 month:
Hormonal birth control
People who use hormonal birth control may experience breakthrough bleeding, which is spotting or bleeding that occurs between periods. Depending on the amount of bleeding, someone may mistake this spotting for a second period.
According to the American College of Obstetrics and Gynecology (ACOG), types of hormonal birth control that can cause breakthrough bleeding include:
- low dose and ultra-low dose oral contraception
- intrauterine devices (IUDs)
- birth control implant
ACOG explains this type of bleeding typically goes away within a few months of starting these types of birth control. Contact an OB-GYN if you have questions or concerns about bleeding that occurs while using hormonal contraception.
Perimenopause
Perimenopause is the phase when your body begins to transition into menopause, when menstruation stops.
A first indicator of perimenopause is often a change in your menstrual cycle. This may include more frequent periods.
If you experience additional periods and your OB-GYN has ruled out other conditions that may be causing bleeding, they may determine you have started perimenopause.
Learn five signs you may be in perimenopause.
Thyroid conditions
Your thyroid produces hormones that regulate how your body uses energy. Thyroid conditions can affect many functions in the body, including menstruation.
If your thyroid is producing too much or too little hormone, it can cause symptoms including heavy or irregular periods.
According to the Office on Women’s Health, an estimated 1 in 8 women will experience thyroid problems.
Learn more about recognizing the signs of thyroid disease.
Other causes of irregular periods
A variety of other conditions can cause irregularities in your menstrual cycle, which may include less frequent or more frequent periods. These include:
- hard exercise or physical training
- extreme changes in weight
- eating disorders, such as bulimia or anorexia nervosa
- polycystic ovarian syndrome (PCOS)
- unmanaged diabetes
- Cushing’s syndrome
- certain medications, including medications for mental health conditions and epilepsy
If you have persistent changes to your menstrual cycle or any unexpected vaginal bleeding that concerns you, contact your OB-GYN.
Vaginal bleeding is different from a period. It occurs at times when bleeding is not expected, such as after menopause or between periods.
Second period vs. vaginal bleeding
It may be difficult to tell whether the bleeding you are experiencing between menstrual cycles is a second period or unexpected vaginal bleeding.
A 2016 research article describes the differences as follows:
| It may be a second period if… | It may be unexpected vaginal bleeding if… |
|---|---|
| It occurs within 5 years of starting your period or 5 years before menopause. | It occurs before puberty, after menopause, or between expected periods during the primary reproductive years. |
| It follows your typical period duration. | It lasts longer than expected or does not stop. |
| It has a blood flow similar to your typical period. | Bleeding is heavier or lighter than usual. |
| You recently began hormonal birth control. | You are or could be pregnant. Bleeding in early pregnancy is common, but it could also be a sign of a complication. |
| You do not experience other unusual symptoms. | You experience additional symptoms, such as abdominal pain, passing of large blood clots, or a fever of 100.4°F (38°C) or higher. |
Causes of vaginal bleeding
Unexpected bleeding between periods that happens frequently could be a sign of an underlying condition. Possible causes of vaginal bleeding include:
- uterine fibroids
- lack of ovulation
- endometriosis
- cervical polyps
- bleeding disorders, such as von Willebrand’s disease
- pelvic inflammatory disease (PID)
- sexually transmitted infection (STI)
- certain cancers, such as endometrial cancer
Learn more about vaginal bleeding causes and when to contact a doctor.
Talk with your OB-GYN if you are frequently having two periods in 1 month so they can make a timely diagnosis and begin appropriate treatment. Also contact your doctor if you have any of the following symptoms:
- fainting
- pain during sexual intercourse
- chronic abdominal pain
- dark clots in menstrual blood
- extremely heavy periods
- more menstrual cramps than usual
- pelvic pain
- spotting frequently in between periods
- shortness of breath
- unexplained weight gain or loss
These symptoms may indicate an underlying condition that requires prompt diagnosis and treatment, such as:
- anemia
- endometriosis
- thyroid disease
- certain cancers
For certain people, it can be normal to have two periods in 1 month. Young teenagers who have just started menstruation or people who are transitioning into menopause may experience irregular periods, which can include more frequent cycles.
In other cases, unexpected vaginal bleeding could indicate an underlying condition. Contact your OB-GYN for bleeding that occurs before puberty, after menopause, during pregnancy, or between periods during primary reproductive years.
If you experience bleeding that occurs with additional symptoms, such as abdominal pain or cramping, passage of blood clots, or signs of infection, contact your OB-GYN right away.
