Understanding the Menstrual Cycle The Menstrual Cycle The menstrual cycle is the monthly series of hormone-driven processes that prepare a woman’s body for pregnancy.e60dc2a1-f33c-4a05-9b50-8e3e8e597629c1f4b5df-857c-40f0-8b3f-a66ce49f0f2f The average cycle lasts 28 days, but it can range from 21 to 38 days. During each menstrual cycle, the uterine lining thickens to prepare for a possible pregnancy, and one egg matures in its follicle.e60dc2a1-f33c-4a05-9b50-8e3e8e597629c1f4b5df-857c-40f0-8b3f-a66ce49f0f2f During ovulation, around halfway through the cycle, the ovary releases the mature egg, which travels down the fallopian tube to the uterus. If a pregnancy doesn’t occur, the uterine lining sheds in a menstrual period. The entire cycle is regulated by estrogen and progesterone — hormones that are released by the ovaries under the direction of the hypothalamus and pituitary gland in the brain.e60dc2a1-f33c-4a05-9b50-8e3e8e597629df87b48a-7a3f-4902-8115-c34ae7ca238f
Starting at puberty, periods become a regular part of a woman’s life.e60dc2a1-f33c-4a05-9b50-8e3e8e59762976aa738b-ad2a-4dac-b2ec-6048118a6bb2 The shedding of uterine tissue and blood typically happens once per cycle — roughly once a month. Each cycle ends with a menstrual period . Some women get more than one period per month, for a variety of reasons. While menstruating twice in a month can be annoying, it doesn’t necessarily signal a problem.
When to Consult a Healthcare Professional When to See a Doctor Two periods in a month usually isn’t cause for concern, especially if it happens consistently and doesn’t come with other symptoms. “If this is new for you or your cycles are usually regular and now suddenly you’re bleeding more frequently, it could be worth checking in with a doctor,” Monteiro says. Symptoms to Watch For Let your doctor know if you get symptoms like these with extra periods:e60dc2a1-f33c-4a05-9b50-8e3e8e597629289ad40c-e6b8-4b17-a3a0-a162eeb7c096 Very heavy bleeding Severe cramps or pelvic pain Unexplained weight gain or loss Dizziness or fainting Abnormal or smelly vaginal discharge
Prevention and Self-Care Strategies Prevention The only way to prevent extra periods is by taking a hormonal birth control method like the pill or IUD. But following a healthy lifestyle is good for your health overall, says Saunders. Monteiro and Saunders suggest trying the following strategies: Eat a nutrient-dense diet that’s heavy in foods like fruits, vegetables, whole grains, and lean protein Do a mix of aerobic and strength-training exercises Avoid smoking and alcohol Get a minimum of seven hours of sleep a night Manage stress with relaxation techniques like meditation, deep breathing, or yoga Also, keep a close watch on your menstrual cycles. If you notice something’s not right, tell your doctor and go in for an evaluation. “Get to the root of the problem, and then focus your treatments on that issue,” Saunders says.
Possible Causes of 2 Menstrual Periods in 1 Month Possible Causes You might have two menstrual periods in a month for many reasons. The simplest explanation is that your menstrual cycle is closer to 21 days, in which case the cycle will end before the calendar month does. “If your cycle is on the shorter side, it is entirely possible to have two periods within one month,” says Anthony C. Monteiro, DO , an obstetrician gynecologist at RWJ Barnabas Health in New Brunswick, New Jersey. Other reasons range from lifestyle changes to medical conditions. Lifestyle Changes and Stress Any major changes to your routine can throw the menstrual cycle out of whack.e60dc2a1-f33c-4a05-9b50-8e3e8e59762988c0129d-a71e-4c71-88cf-7cc9604ecd48 Shifts in diet, exercise, sleep, or weight can all influence cycle length. Stress is a big contributor to menstrual irregularities.e60dc2a1-f33c-4a05-9b50-8e3e8e597629b7e0832b-5c99-43de-945d-b0cb57b94887 When the body is under stress, it releases the hormone cortisol , which can disrupt the normal release of estrogen and progesterone. That hormonal shift can lead to more or less frequent periods. Hormonal Imbalance Estrogen and progesterone play big roles in the menstrual cycle.e60dc2a1-f33c-4a05-9b50-8e3e8e597629aa5f8e7b-c7cb-4a7c-b194-2a8522a0f19d Rising estrogen levels in the middle of the cycle trigger the release of luteinizing hormone (LH) from the pituitary gland, which causes an egg to mature and ovulation to occur. Both estrogen and progesterone prepare the uterine lining for a possible pregnancy. If no pregnancy happens, levels of these hormones drop and a period starts. An imbalance in levels of estrogen and progesterone, whether from age, a medical condition, or medication, can make periods come more frequently than usual.e60dc2a1-f33c-4a05-9b50-8e3e8e597629aa5f8e7b-c7cb-4a7c-b194-2a8522a0f19d Birth Control and Medications A pack of birth control pills contain a mix of active (containing estrogen and progesterone) and inactive pills.e60dc2a1-f33c-4a05-9b50-8e3e8e597629cf8cdb56-18ba-4674-8c36-f762474a25d2 Periods come on days when you’re taking the inactive pills. Continuous birth control pills, which are mainly active pills, reduce the number of periods or eliminate them entirely. “However, it is possible for an individual to have unexpected or bothersome bleeding while on birth control, in which case they should check in with their doctor,” Dr. Monteiro says. Some women bleed a little while taking active pills. This isn’t a period. Doctors call it breakthrough bleeding.e60dc2a1-f33c-4a05-9b50-8e3e8e5976291edfc4af-9314-430e-a6b8-b67e5ac46691 Starting, stopping, or changing to a different form of hormonal birth control can lead to more or fewer periods because it disrupts the normal menstrual cycle.e60dc2a1-f33c-4a05-9b50-8e3e8e597629857f5090-0e32-4892-afa5-4ef76a2477bd Women may have irregular periods for up to six months after they go off the pill. Other forms of hormonal birth control, like the intrauterine device (IUD) , injections, and implants can also lead to irregular periods, says Rhiana Saunders, MD , a reproductive endocrinologist and infertility specialist with Aspire Houston Fertility Institute in Texas. So can some other types of medicines, like anti-seizure drugs and antipsychotics .e60dc2a1-f33c-4a05-9b50-8e3e8e5976294d432d5f-e744-4d41-93a0-aa985ae6b444
Resources We Trust Cleveland Clinic: What Is Period Underwear and Does It Work? Mayo Clinic: Menstrual Cycle: What’s Normal, What’s Not Planned Parenthood: Birth Control NHS: Irregular Periods Office on Women’s Health: Uterine Fibroids
Age-Related Factors Both puberty and perimenopause are times when hormone levels fluctuate. It’s common to have irregular or extra periods during both of these life transitions, says Monteiro. When the egg supply dwindles heading into menopause , the ovaries become less responsive to signals from the brain. As a result, women may “ovulate at shorter intervals or at chaotic intervals, and have unpredictable bleeding patterns,” says Dr. Saunders. Medical Conditions Some conditions cause extra periods or longer bleeding. “This is typically due to disruptions to hormones or the endometrial lining,” says Monteiro. Medical conditions that affect menstrual periods include: Polyendocrine Metabolic Ovarian Syndrome (PMOS) PMOS causes small fluid-filled sacs to form on the ovaries.e60dc2a1-f33c-4a05-9b50-8e3e8e5976297a4f54e4-e879-4737-9f80-f47bd0de7906 Uterine Fibroids and Polyps Fibroids are noncancerous growths in the lining of the uterus that cause heavy or unpredictable periods and pain.e60dc2a1-f33c-4a05-9b50-8e3e8e597629bbc29fab-07c7-4cb6-ad4e-0401e197dcab Endometriosis In endometriosis , tissue that resembles the lining of the uterus grows in other parts of the abdomen.e60dc2a1-f33c-4a05-9b50-8e3e8e5976293a58d3b1-6211-4e4b-adbc-89571aa2528c Thyroid Disorders The thyroid gland helps control menstrual cycles. A thyroid disorder that leads to excessive or inadequate thyroid hormones can make periods irregular.e60dc2a1-f33c-4a05-9b50-8e3e8e597629125cc66f-5a82-4481-a8e8-2a91038f5c48 Note: Formerly called polycystic ovary syndrome, PMOS was adopted as the condition’s name in May 2026 f ollowing a global consensus to highlight the metabolic roots of the condition.