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.

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 disorderThe 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.

SubscribeWhat causes a late period with a negative pregnancy test?Medically reviewed by Tahirah Redhead MPAS, PA-C, MPH — Written by Amanda Barrell — Updated on March 24, 2025Short-term causesLong-term causesWith dischargeWith crampsPregnancy test accuracyContacting a doctorFAQSummaryA 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.Short-term causes of missed periodsViktor Solomin/StocksyIrregular 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 disorderThe 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).Many other resources are also available, including:The National Association of Anorexia Nervosa and Associated DisordersF.E.A.S.T., which provides support and educational resources to friends and family who want to help someone living with an eating disorder Stress Intense stress can affect the part of the brain that controls reproductive hormones, causing ovulation and periods to Stop trusted 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:very light, very heavy, or unpredictable bleeding during periods skin conditions, such as acne, dark patches, or skin tags being overweight or having obesity thinning hair sleep apnea difficulty getting pregnant excess hair on the face, back, or thigh increases in vaginal discharge cramping Excessive Exercise amenorrhea is Common trusted 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.