What Can Delay Your Period?

Here are reasons why your period is erratic or missing altogether—and what to do about it.

If you have regular menstrual cycles, you may occasionally find that it's later than usual. While you might attribute the cause to having had an illness like the flu or a possible pregnancy, other factors can result in a late period.

Poor sleep, vigorous exercise, traveling across time zones, or weight changes are some of the reasons you may see a delay in having your period. Here's what you need to know, including how much of a delay is normal and when to see a healthcare provider.

1. Exercising Rigorously

You may see a delay in your periods from heavy exercise. Frequent vigorous exercise can be responsible for irregular periods and missed periods. You may also have irregular periods if you start exercising again after you haven't in a while.

Exercise puts physical stress on your body. This stress tells your brain to stop producing reproductive hormones.

One of those hormones is gonadotropin-releasing hormone (GnRH). This hormone is responsible for the timing of your periods. If your brain doesn't release or slowly releases GnRH, you can stop having periods—known as amenorrhea.

More About Ameorrhea

Amenorrhea is the absence of a period often caused by stress, weight loss, or frequent exercise. Other symptoms that may be associated with amenorrhea depend on the cause, and can include:

  • Changes in eyesight
  • Extra facial hair
  • Hair loss
  • Headache
  • Lack of breast development
  • Milky breast discharge

2. Weight Changes

Estrogen is produced mainly from adipose tissue (the tissue that makes up fat) after menopause. However, any extra fat can make estrogen at any time in a person's life. This means that when levels of fat in the body increase, estrogen levels also increase. As a result, the extra estrogen affects your menstrual cycle, leading to heavy periods and missed or irregular ones.

Too much estrogen for an extended period can also increase your risk of breast and endometrial cancer. However, going on the pill may help. Oral contraceptives have been associated with lowering the risk of developing endometrial cancer.

Additionally, if you lose weight too quickly, this may lead to irregular periods as well. Estrogen is necessary for building the uterine lining for a potential pregnancy during the menstrual cycle. When you lose a lot of weight, your body doesn't produce enough estrogen.

3. Feeling Stressed Out

Feelings of stress can delay your period. Research has shown that people experiencing high stress levels were also experiencing irregular periods.

When stress affects the timing of a period, it can affect fertility. Those who are stressed out may have a more challenging time trying to conceive or have a healthy pregnancy.

Beyond irregular periods, stress can also affect your menstrual cycle in other ways. For example, individuals under high stress may experience more painful periods and changes in how long their cycles are.

4. Fluctuating Hormones

Issues with the thyroid—a gland in your neck—can affect the regularity of your period. Thyroid hormones are responsible for your body's energy control and affect many organs. When thyroid hormone levels are up or down, your body functioning can change—including your menstrual cycle functioning.

For those with an overactive thyroid gland—meaning they produce too much thyroid hormone—their periods tend to be shorter and occur more frequently. The opposite is true for those who don't make enough thyroid hormone and have an underactive thyroid. Their periods tend to be less frequent.

5. Exposure to Pesticides

Pesticides can be associated with irregular periods. One study's participants had been exposed to pesticides from working on farmland, living on it, or both.

Many had exposure to endocrine-disrupting chemical pesticides, a pesticide known to cause menstrual irregularities. Participants reported irregularities in their cycle length and the absence of their period for more than 90 days.

Some classes of chemicals can bind to receptors (molecules on the surface of a cell) for estrogen in the body. As a result, they can copy how estrogen functions in the body.

6. Breastfeeding

If you choose to breastfeed consistently, you may find that your period doesn't come back right away. This is known as lactational amenorrhea. Lactational amenorrhea happens after a person gives birth and increases the time it takes for a person to get pregnant again. For that reason, some individuals use it as a birth control method.

More About Lactational Amenorrhea

Using the lactational amenorrhea method (LAM) is meant to be temporary. If someone wants to use LAM as contraception, three conditions must be met to ensure that LAM is safe and effective:

  1. Amenorrhea after giving birth
  2. Breastfeeding full-time or nearly full-time (no more than 4-6 hours between feedings)
  3. Breastfeeding for 6 months after giving birth

However, if you are not using LAM and your period has not resumed after giving birth, consult a healthcare provider. They can help determine what might be causing a delay in your period.

7. Your Age

Your period may not get regular until your 20s. However, as you approach menopause, periods may become irregular again.

While you probably expect your period to become less frequent as you approach menopause, it can vary with its timing. For example, your period may stop for a few months and then return out of nowhere.

8. Sleeping Poorly

Getting less sleep can make you feel off, but subpar slumber patterns can throw off your cycle. What's more, sleep quality can get worse for individuals who experience premenstrual symptoms.

One study analyzed data from 579 participants concerning their menstrual cycles and how regularity was related to sleep duration, quality, and fatigue. The researchers found that heavier bleeding and irregular periods were related to:

  • Depression
  • Fatigue
  • Sleeping for a shorter time
  • Stress
  • Worse sleep

9. Traveling Across Time Zones

Estrogen levels change throughout your period. There is also an inverse relationship between estrogen and melatonin. Melatonin levels are down when estrogen levels are up, and vice versa.

Your brain produces melatonin to signal your body that it's time to go to bed. When you travel to another time zone, your body releases melatonin as if you're still at home, even if it's broad daylight in your new location.

10. Certain Health Conditions

You may also experience irregular periods if you have different health conditions. These conditions may include:

  • Eating disorders (including anorexia nervosa, bulimia nervosa, and binge eating disorder)
  • Pelvic inflammatory disease (PID)
  • Polycystic ovary syndrome (PCOS)
  • Primary ovarian insufficiency (POI)
  • Uncontrolled diabetes

You might experience irregular periods for different reasons depending on the health conditions. For example, you may have an infection of reproductive organs related to PID or hormonal imbalances if you have PCOS.

Looking for support?

If you or a loved one are coping with an eating disorder, contact the National Eating Disorders Association (NEDA) Helpline for support at 1-800-931-2237. For more mental health resources, see our National Helpline Database.

If this is an emergency call:

911

How Much Delay Is Normal?

It's normal for your cycle to be a couple of days off. Additionally, your menstrual cycle can still be considered regular if the timing is off for more or less than two to 20 days.

When To Contact a Healthcare Provider

A delayed period that's a few days off is generally nothing to worry about. However, you'll want to see a healthcare provider if:

  • Your period is consistently late
  • Your period is early by more than one week
  • You get irregular periods when you usually have regular ones
  • You miss more than three periods in a row or within a year

What Might Help Regulate Your Period?

Despite all the possible causes of irregular periods, some ways may help regulate your period, such as:

  • Getting enough quality sleep: Make sure that you get quality sleep. Quality sleep can look like getting enough sleep and having a consistent sleep schedule.
  • Maintaining a healthy weight: A healthy body weight, which will vary individually, can help with period regulation. Eating healthy foods and being physically active are the main ways to manage weight.
  • Relieving stress: Activities like reading, yoga, or doing anything you find enjoyable can help reduce stress.
  • Using hormonal birth control: Oral contraceptives typically contain estrogen and progestin. These hormones prevent the ovaries from releasing an egg. Other types of contraception, like intrauterine devices and implants, can also be used to regulate periods.

A Quick Review

Your period could be delayed by a few days, but that doesn't automatically mean it's irregular. However, many things can cause your period to be delayed or irregular. Some causes include health conditions like PID or PCOS, breastfeeding, weight changes, and hormone changes.

Hormonal birth control, getting enough sleep, and stress-reducing activities are a few potential ways to regulate your menstrual cycle. If you experience any issues with your menstrual cycle, consult a healthcare provider.

Frequently Asked Questions

  • What should I do if I have a late period?

    See a healthcare provider if you're unsure why your period is late or if you think you may be pregnant. You should also consult a provider if your period is consistently late or if you're used to having regular periods but start having irregular ones.

  • Can your period be delayed by 10 days?

    Yes. Additionally, your period could be delayed by up to 20 days without being considered irregular.

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28 Sources
Health.com uses only high-quality sources, including peer-reviewed studies, to support the facts within our articles. Read our editorial process to learn more about how we fact-check and keep our content accurate, reliable, and trustworthy.
  1. Office on Women's Health. Physical activity and your menstrual cycle.

  2. Sophie Gibson ME, Fleming N, Zuijdwijk C, Dumont T. Where have the periods gone? The evaluation and management of functional hypothalamic amenorrheaJCRPE. 2020;12(1):18-27. doi:10.4274/jcrpe.galenos.2019.2019.S0178

  3. Welt CK. Patient education: absent or irregular periods (beyond the basics). In:UpToDate. UpToDate; 2023.

  4. Eunice Kennedy Shriver National Institute of Child Health and Human Development. What are the symptoms of amenorrhea?

  5. Bhardwaj P, Au CC, Benito-Martin A, et al. Estrogens and breast cancer: Mechanisms involved in obesity-related development, growth and progressionThe Journal of Steroid Biochemistry and Molecular Biology. 2019;189:161-170. doi:10.1016/j.jsbmb.2019.03.002

  6. Office on Women's Health. Period problems.

  7. Zhao H, Zhou L, Shangguan AJ, Bulun SE. Aromatase expression and regulation in breast and endometrial cancerJournal of Molecular Endocrinology. 2016;57(1):R19-R33. doi:10.1530/JME-15-0310

  8. Burchardt NA, Shafrir AL, Kaaks R, Tworoger SS, Fortner RT. Oral contraceptive use by formulation and endometrial cancer risk among women born in 1947–1964: The Nurses’ Health Study II, a prospective cohort studyEur J Epidemiol. 2021;36(8):827-839. doi:10.1007/s10654-020-00705-5

  9. Office on Women's Health. Weight loss and women.

  10. Nagma S, Kapoor G, Bharti R, et al. To evaluate the effect of perceived stress on menstrual functionJ Clin Diagn Res. 2015;9(3):QC01-QC03. doi:10.7860/JCDR/2015/6906.5611

  11. American Psychological Association. Stress effects on the body.

  12. Keestra S, Högqvist Tabor V, Alvergne A. Reinterpreting patterns of variation in human thyroid functionEvolution, Medicine, and Public Health. 2021;9(1):93-112. doi:10.1093/emph/eoaa043

  13. MedlinePlus. TSH (thyroid-stimulating hormone) test.

  14. Varnell RR, Arnold TJ, Quandt SA, et al. Menstrual cycle patterns and irregularities in hired Latinx child farmworkersJournal of Occupational & Environmental Medicine. 2021;63(1):38-43. doi:10.1097/JOM.0000000000002065

  15. Kumar V, Yadav CS, Banerjee BD. Xeno-estrogenic pesticides and the risk of related human cancersJoX. 2022;12(4):344-355. doi:10.3390/jox12040024

  16. Calik-Ksepka A, Stradczuk M, Czarnecka K, Grymowicz M, Smolarczyk R. Lactational amenorrhea: neuroendocrine pathways controlling fertility and bone turnoverIJMS. 2022;23(3):1633. doi:10.3390/ijms23031633

  17. Centers for Disease Control and Prevention. Lactational amenorrhea method.

  18. Office on Women's Health. Your menstrual cycle.

  19. Baker FC, Lee KA. Menstrual cycle effects on sleepSleep Medicine Clinics. 2022;17(2):283-294. doi:10.1016/j.jsmc.2022.02.004

  20. Kennedy KER, Onyeonwu C, Nowakowski S, et al. Menstrual regularity and bleeding is associated with sleep duration, sleep quality and fatigue in a community sampleJournal of Sleep Research. 2022;31(1). doi:10.1111/jsr.13434

  21. Gupta P. Menstrual cycle effects on sleepClin J Obstet Gynecol. 2022;5(2):042-043. doi:10.29328/journal.cjog.1001105

  22. National Center for Complementary and Integrative Health. Melatonin: what you need to know.

  23. Roach GD, Sargent C. Interventions to minimize jet lag after westward and eastward flightFront Physiol. 2019;10. doi:10.3389/fphys.2019.00927

  24. Merck Manual Professional Version. Female reproductive endocrinology.

  25. Kim JH. Body weight changes in obese women and menstruationEndocrinol Metab. 2017;32(2):219. doi:10.3803/EnM.2017.32.2.219

  26. Centers for Disease Control and Prevention. Healthy weight, nutrition, and physical activity.

  27. MedlinePlus. Birth control pills.

  28. DeMaria AL, Sundstrom B, Meier S, Wiseley A. The myth of menstruation: how menstrual regulation and suppression impact contraceptive choiceBMC Women’s Health. 2019;19(1):125. doi:10.1186/s12905-019-0827-x

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