A period can be late for many reasons, including changes in a person’s dietary or exercise regime. A person may choose to take a pregnancy test if their period is late. However, the result can be negative if a person is pregnant but takes the test too soon.

The ovaries release an egg during ovulation, approximately every 28 days. If no sperm fertilizes the egg, a person’s period usually starts about 14 days later.

While a missed period is one of the first signs of pregnancy, there are various other reasons why it can occur.

Menstrual irregularities, such as missed or late periods, occur in many women of childbearing age. They can result from a range of conditions besides pregnancy, including hormonal imbalances, hormonal birth control, stress, weight loss, trauma, and certain health conditions.

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Irregular periods are standard, especially during the first few yearsTrusted Source of a person’s period. Many circumstances may affect the regularity of the menstrual cycle, including:

Weight changes due to an eating disorder

The rapid gain or loss of significant weight can lead to hormonal imbalances. Eating disorders such as anorexia nervosa may cause dysfunction in the hypothalamic-pituitary-ovarian axis, which causes changes to hormone levels and may cause periods to be irregular or stop altogether.

Help is available

Eating disorders can severely affect the quality of life of people living with these conditions and those close to them. Early intervention and treatment greatly improve the likelihood of recovery.

Anyone who suspects they or a loved one may have an eating disorder can contact the National Alliance for Eating Disorders, which offers a daytime helpline staffed by licensed therapists and an online search tool for treatment options.

For general mental health support at any time, people can call the Substance Abuse and Mental Health Services Administration 24 hours a day at 1-800-662-4357 (or 1-800-487-4889 for TTY).

Many other resources are also available, including:

Stress

Intense stress can affect the part of the brain that controls reproductive hormones, causing ovulation and periods to stopTrusted Source.

Once the cause of the stress eases or the person learns coping strategies to manage it, their regular cycle may return.

Producing too much prolactin — nursing

Prolactin is a hormone that the body usually makes during nursing. It can affect menstruation, and this is why most people who nurse do not have periods. Periods typically return once a person stops nursing.

A milky discharge from the nipples can signify that the body is making an abnormally high amount of prolactin in people who are not nursing. Doctors can treat excessive prolactin production with medication.

Polycystic ovary syndrome (PCOS)

People with PCOS have a hormonal imbalance that can affect their overall health and appearance, in addition to causing ovarian cysts. This can cause a person to have irregular periods or stop having them entirely.

Up to 10%Trusted Source of women of childbearing age have PCOS and may have enlarged ovaries with clusters of small, benign cysts.

People with PCOS may experience other symptoms as well as missing periods. These include:

Excessive exercise

Amenorrhea is commonTrusted Source among athletes who train intensely. Intense exercise causes the body to release stress hormones, which can interfere with producing reproductive hormones and cause irregular or missed periods.

Exercises that may cause a person to have low body weight, such as long-distance running or intensive ballet, are more likely than others to cause amenorrhea.

Hormonal birth control

Hormonal birth control works by suppressing ovulation, which means a person may experience changes to their period, including having periods that are early, late, or stopped altogether.

Some underlying health conditions may cause a person to stop having periods altogether.

Thyroid problems

The thyroid gland produces hormones to control the body’s metabolism.

Hypothyroidism, or an underactive thyroid, is the thyroid not producing enough of these hormones. Hyperthyroidism, or an overactive thyroid, results in the levels of thyroid hormones in the body being too high. Both conditions can affectTrusted Source the frequency of a person’s period.

Doctors can usually diagnose thyroid problems using a simple blood test.

Thyroid disorders can cause a person to miss their period but may also cause other symptoms, including;

  • fatigue, or extreme tiredness
  • hair loss
  • unexplained weight gain or loss
  • constantly feeling cold or being warm all the time

Perimenopause

People enter menopause when they have not had a period for at least 12 months. The average age of people entering menopause in the United States is 52Trusted Source. However, the transition to menopause, known as perimenopause, may cause symptoms that begin at a younger age.

Other symptoms of perimenopause include:

Diabetes

People with type 2 diabetes are at an increased risk of irregular menstrual periods due to anovulation, which happens when an ovary does not release an egg into the fallopian tube. When this occurs, a person will not have a menstrual period.

Learn more about diabetes and periods here.

Primary Ovarian Insufficiency (POI)

POI is a person’s ovaries stopping working as expected before they reach 40 years oldTrusted Source. POI is not the same as early menopause or perimenopause. People with POI may not get their monthly periods or may experience irregular periods.

Cushing’s syndrome

Cushing’s syndrome is a hormonal condition that occurs due to exposure to too much cortisol or medications similar to cortisol. People with Cushing’s syndrome may experience irregular or stopped periods.

Some people may experience vaginal discharge alongside missed periods.

Potential causes of this include:

In some instances, a person may experience abdominal cramps and missing periods.

Potential causes of this include:

Home pregnancy tests can sometimes give a false negative result, indicating that someone is not pregnant when they are. The accuracy of a home pregnancy test varies depending on how and when a person takes it.

Some of the reasons a test may give a false-negative result include:

Taking a test too soon

Home pregnancy tests look for the presence of human chorionic gonadotropin (hCG) in urine. Although some tests can detect hCG from the first day of a missed period, they are generally more accurate later.

Low hormones

Tests are usually more precise first thing in the morning because the urine is less diluted at this time, making hCG easier to detect.

If a person starts to experience irregular periods, they should contact their doctor immediately. This includes having periods more frequently than every 24 daysTrusted Source or less often than every 38 days.

Individuals may miss a period for several reasons, including specific medical conditions, so it is essential to get a proper diagnosis.

To ensure that a home pregnancy test is accurate, people should follow the instructions on the packaging and wait until at least 1 week after the first day of the missed period before taking the test.

Can a person still be pregnant if the test is negative and there is no period?

Home pregnancy tests can be unreliable, and a negative test may mean the hCG levels are not high enough for the test to detect pregnancy. Contacting a doctor for a test is the best way to know if a person is pregnant, particularly if there is no period.

What is the maximum delay in periods if not pregnant?

If a person does not have a period for 6 weeks, this is usually a missed period. Speak with a doctor or healthcare professional to understand why a missed period may have occurred.

Menstrual irregularities such as missed or late periods are common, especially in younger people who are menstruating. If a person misses a period and is not pregnant, it could be due to situational factors such as increased stress, intense exercise, starting new hormonal birth control, or experiencing sudden weight changes.

In some cases, a missed period may be due to a chronic condition such as a thyroid condition, type 2 diabetes, Cushing’s syndrome, or PCOS.

If a person misses more than three periods in a row, they should contact a healthcare professional to make sure their reproductive system is healthy and functioning correctly.