A late period can be unsettling, especially when pregnancy isn’t a factor. Your menstrual cycle responds to many influences throughout your body, and understanding the common causes behind irregular periods can help you know when to seek professional guidance. This guide explores 12 reasons your period might be delayed and explains how an OBGYN can help identify the underlying cause.
Understanding Your Menstrual Cycle
Your menstrual cycle operates through a complex interaction between your brain, ovaries, and uterus. Hormones like estrogen and progesterone regulate ovulation and menstruation, and any disruption to this system can result in menstrual irregularities. A typical cycle ranges anywhere between 21 and 35 days, and occasional variation is normal for most women.
When your period arrives later than expected for two or more consecutive cycles, this signals an abnormal menstrual cycle that deserves attention. Tracking your cycle through an app or calendar helps you notice patterns and provides valuable information during your appointment at an OBGYN clinic.
12 Reasons Your Period May Be Late
The following causes represent the most common explanations for delayed menstruation beyond pregnancy. Some involve lifestyle factors you can address on your own, while others require evaluation by OBGYN specialists.
1. Chronic Stress
Chronic stress triggers your body’s cortisol production, which can suppress the hormones responsible for ovulation. When ovulation is delayed or skipped, your period follows suit. Work pressures, family challenges, or major life transitions all contribute to stress-related menstrual problems.
High cortisol levels interfere with the hypothalamus, the part of your brain that signals your ovaries to release an egg. Addressing stress through exercise, adequate sleep, or counseling often helps restore regular cycles within a few months.
2. Significant Weight Loss
Your body requires adequate fat stores to produce estrogen, so extreme dieting or eating disorders may cause periods to stop entirely. Women who lose more than 10% of their body weight quickly often experience delayed or missed periods.
Low body weight signals to your brain that conditions aren’t optimal for pregnancy, leading your reproductive system to pause. Working with your OBGYN and a nutritionist can help you find a healthy balance that supports regular menstruation.
3. Rapid Weight Gain
On the opposite end, rapid weight gain can lead to excess estrogen production, creating hormonal imbalances that affect ovulation. Obesity increases the risk of menstrual irregularities because fat tissue produces additional estrogen that disrupts normal hormone cycling.
Gradual, sustainable weight management often helps restore cycle regularity. Your provider can recommend approaches that support both your overall health and reproductive function.
4. Excessive Exercise
Intense athletic training places significant physical demands on your body. Female athletes, dancers, and women who exercise strenuously may experience what’s called hypothalamic amenorrhea. This condition occurs when the body perceives physical stress and conserves energy by reducing reproductive hormone production.
If you’ve recently increased your workout intensity or duration and noticed irregular periods, your exercise routine might be contributing to the changes. Your OBGYN can evaluate your training schedule and recommend modifications that support both your fitness goals and reproductive health.
5. Polycystic Ovary Syndrome (PCOS)
PCOS affects approximately 10% of women of reproductive age and represents one of the most common causes of menstrual problems. This condition creates hormonal imbalances that prevent regular ovulation, leading to infrequent or prolonged periods. Many women with PCOS go months between periods or experience unpredictable cycle timing.
Women with PCOS often have elevated androgen levels, which may cause acne, excess facial hair, or thinning hair on the scalp. Other symptoms include weight gain concentrated around the midsection and difficulty losing weight. Insulin resistance frequently accompanies PCOS and increases the risk of developing type 2 diabetes over time.
An OBGYN can diagnose PCOS through blood tests, ultrasound imaging, and a review of your symptoms. Treatment options include lifestyle modifications, hormonal contraceptives, and medications to regulate ovulation. With proper OBGYN care, women with PCOS can manage their symptoms effectively and maintain reproductive health.
ALSO READ: When to See an OBGYN for PCOS
6. Thyroid Disorders
Your thyroid gland produces hormones that regulate metabolism throughout your body, including your reproductive system. Both hypothyroidism (underactive thyroid) and hyperthyroidism (overactive thyroid) can cause an abnormal menstrual cycle. Thyroid disorders are among the most treatable causes of cycle irregularity.
An underactive thyroid slows bodily functions and may cause heavy, prolonged periods or missed periods altogether. Women with hypothyroidism often experience fatigue, weight gain, and cold intolerance alongside their menstrual irregularities. An overactive thyroid can make periods lighter and less frequent, and may cause unintended weight loss, rapid heartbeat, and anxiety.
Simple blood tests measure thyroid hormone levels, and medication effectively manages most thyroid conditions. If you’re experiencing cycle changes alongside fatigue, weight fluctuations, or temperature sensitivity, mention these symptoms during your visit to an OBGYN clinic. Once thyroid levels normalize with treatment, menstrual regularity typically improves.
7. Premature Ovarian Insufficiency
Premature ovarian insufficiency occurs when the ovaries stop functioning normally before age 40. This condition affects hormone production and egg release, causing irregular periods that may eventually stop completely.
Women with this condition may experience symptoms similar to menopause, including hot flashes, night sweats, and vaginal dryness. While premature ovarian insufficiency cannot be reversed, OBGYN specialists can recommend hormone therapy to manage symptoms and discuss fertility options if pregnancy is desired.
8. Uterine Fibroids
Fibroids are noncancerous growths that develop in or around the uterus. While they more commonly cause heavy bleeding, fibroids can sometimes contribute to menstrual problems by affecting hormone balance or interfering with normal uterine function.
Depending on their size and location, fibroids may cause pelvic pressure, frequent urination, or lower back pain. Your provider at Roswell Ob/Gyn, LLC can detect fibroids through a pelvic exam or ultrasound and discuss treatment options ranging from medication to minimally invasive surgery.
9. Endometriosis
Endometriosis occurs when tissue similar to the uterine lining grows outside the uterus. This condition causes inflammation and scarring that can affect ovarian function and hormone production, potentially leading to an abnormal menstrual cycle.
Common symptoms include severe pelvic pain, painful periods, and discomfort during intercourse. Endometriosis also contributes to fertility challenges for many women. Diagnosis often requires laparoscopy, a minimally invasive surgical procedure that allows direct visualization of the pelvic organs.
10. Hormonal Contraceptives
Birth control pills, patches, injections, and hormonal IUDs all influence your menstrual cycle. Starting, stopping, or switching contraceptive methods frequently causes temporary menstrual irregularities. Some hormonal options intentionally reduce or eliminate periods, which is medically safe.
If you’ve recently changed your birth control method and notice irregular periods, give your body two to three months to adjust. Your OBGYN can help determine if your current contraceptive is the right fit.
ALSO READ: Signs of Hormonal Imbalance in Women
11. Certain Medications
Beyond contraceptives, several medication categories can delay menstruation. Antipsychotics, antidepressants, and some blood pressure medications affect hormone levels that regulate your cycle. Chemotherapy and radiation treatments also commonly cause menstrual problems.
Always inform your OBGYN about all medications you take, including supplements and over-the-counter drugs. This information helps identify potential causes of cycle changes.
12. Perimenopause
The transition to menopause typically begins in your 40s, but can start earlier for some women. During perimenopause, estrogen levels fluctuate unpredictably, causing cycles to become irregular before periods eventually stop.
Perimenopause may last several years, and symptoms vary widely. Some women experience minimal changes, while others deal with significant menstrual irregularities, hot flashes, sleep disruption, and mood changes. Your OBGYN can confirm perimenopause through symptom review and blood tests and recommend strategies to manage symptoms.
When to Schedule an Appointment
While occasional cycle variation is normal, certain situations warrant prompt evaluation by an OBGYN. Schedule an appointment if you experience any of the following:
| Concern | Why It Matters |
| No period for 90 days (not pregnant) | May indicate an underlying hormonal or medical condition |
| Sudden change in cycle pattern | Could signal thyroid issues, PCOS, or other conditions |
| Severe pelvic pain | May suggest endometriosis, ovarian cysts, or other reproductive concerns |
| Heavy bleeding, soaking through protection hourly | Requires evaluation for fibroids, polyps, or hormonal imbalances |
| Bleeding between periods | Can indicate polyps, infection, or other uterine abnormalities |
| Perimenopause symptoms affecting quality of life | Treatment options can provide relief |
Keeping a record of your cycle dates, flow heaviness, and any associated symptoms provides helpful information for your OBGYN clinic visit.
ALSO READ: Heavy Periods: Understanding the “Why” and Knowing When to Seek Care
How Your OBGYN Evaluates Irregular Periods
During your appointment, your provider will review your medical history, menstrual patterns, and current symptoms. The evaluation typically includes a physical exam and may involve:
- Blood tests to check hormone levels, thyroid function, and other indicators
- Pelvic ultrasound to visualize the uterus and ovaries
- Additional imaging or procedures based on initial findings
OBGYN specialists use this information to identify the cause of your abnormal menstrual cycle and develop a personalized treatment plan. Many conditions causing irregular periods respond well to treatment, and early evaluation helps prevent complications.
Take the Next Step With Roswell Ob/Gyn, LLC
Understanding why your period is late empowers you to make informed decisions about your health. Many causes of menstrual problems are treatable once properly diagnosed, and your OBGYN serves as your partner in finding answers. Early evaluation often leads to simpler treatment options and better outcomes.
At Roswell Ob/Gyn, LLC, our team provides comprehensive OBGYN care for women at every stage of life. We offer thorough evaluation and evidence-based treatment for menstrual irregularities and other gynecological concerns at convenient locations in Alpharetta, Atlanta, Canton, and Cumming, GA. Our providers take time to listen to your concerns and explain your options clearly.
Don’t wait to address cycle changes that concern you. Schedule an appointment with our experienced providers to discuss your symptoms and explore your options. Our caring team is ready to help you understand your body and support your reproductive health.
