Delayed Period: 11 Possible Causes and What to Do Next

Quick answer

A delayed period is common and usually not serious. Take a pregnancy test first, since that is the single most common cause. If it is negative, the usual reasons are stress, weight change, intense exercise, PCOS, thyroid problems, breastfeeding, or recently starting or stopping contraception. See a doctor if you have missed three periods in a row, or have pain, unusual discharge or milk-like nipple discharge.

Key takeaways

• Test for pregnancy first, even if you think it is unlikely. No contraceptive method is fully reliable, and it changes everything else you would do.

• Thyroid disorders are one of the most commonly missed causes. Both an underactive and an overactive thyroid disrupt periods, and a single blood test identifies it.

• A cycle of 21 to 35 days is normal. Variation of a few days month to month is normal too, so one late period rarely means anything.

• Three missed periods in a row needs investigation, whatever your age and whatever you think the reason is.

• Some causes are quietly important. Milk-like nipple discharge with irregular periods, or periods that stop before 40, both need proper assessment rather than reassurance.

What counts as a delayed period?

A few days late is not a problem. Cycles shift with illness, travel, stress, sleep and season. What matters is a persistent pattern rather than a single late month.

In the first two years after periods begin, and in the years approaching menopause, irregularity is expected and usually needs no treatment.

The first step: take a pregnancy test

Do this before anything else, even if you use contraception, even if you had a period last month, and even if you feel certain you are not pregnant. Pregnancy is by far the most common cause of a missed period, and every other investigation depends on ruling it out.

• Test with first morning urine, from the day your period was due

• Any line in the test window is positive, however faint

• If negative and your period still has not come, repeat after a week

• If your cycles are irregular and you cannot count a due date, test about three weeks after unprotected sex

• If you have had an hCG trigger injection for fertility treatment, follow your clinic's testing date, since it can cause a false positive for up to about two weeks

If the test is positive and you have severe one-sided pain, shoulder tip pain, faintness or heavy bleeding, go to a hospital. That combination can indicate an ectopic pregnancy and is an emergency.

11 possible causes of a delayed period

1. Pregnancy

The most common cause, and the first to rule out. Along with a missed period you may notice breast tenderness, nausea, tiredness or a heightened sense of smell, though many women notice nothing at all. A positive test means booking antenatal care and starting folic acid straight away.

2. Stress, anxiety or depression

Significant emotional or physical stress delays ovulation, which delays the period that follows it. Exam pressure, bereavement, job loss, relocation and illness are all common triggers. Cycles usually return on their own once the stressor eases, though it can take a couple of months.

3. PCOS

Polycystic ovary syndrome is one of the most common hormonal causes of long or unpredictable cycles in Indian women. Other clues are acne, excess facial or body hair, hair thinning at the scalp, and difficulty losing weight. Diagnosis involves blood tests and usually a pelvic ultrasound, and it is very manageable once identified.

4. Thyroid disorders

Both an underactive and an overactive thyroid disrupt the menstrual cycle. Look for tiredness, weight change, hair fall, feeling unusually cold or hot, constipation or loose stools. A single TSH blood test identifies it, and it is inexpensive, widely available and treatable. This is the cause most often missed.

5. Significant weight change, in either direction

Both substantial weight loss and weight gain disrupt the hormonal signalling that drives ovulation. Very low body weight, restrictive dieting and undernutrition can stop periods altogether, while obesity commonly causes long, unpredictable cycles. Losing 5 to 10 percent of body weight often restores regularity where weight is the issue, and restoring adequate nutrition usually brings periods back where under-eating is.

6. Intense exercise

Heavy training, particularly combined with inadequate calorie intake, commonly delays or stops periods. It is most often seen in athletes and during intensive training phases. Reducing intensity and eating enough to match the workload usually resolves it.

7. Starting, stopping or changing contraception

Pills, injections, implants and hormonal IUDs all change bleeding patterns, sometimes substantially. After stopping, cycles can take several months to settle, and longer after contraceptive injections. Emergency contraception commonly shifts the next period earlier or later by days to a couple of weeks. If a period is more than a week late after emergency contraception, take a pregnancy test.

8. Medications

Several medicines affect cycles, including some antipsychotics, antidepressants, anti-nausea drugs, steroids, chemotherapy and certain epilepsy medications. Never stop a prescribed medicine yourself. Ask your doctor whether the timing fits and whether an alternative exists.

9. Raised prolactin

Prolactin is the hormone that supports milk production, and raised levels outside breastfeeding suppress ovulation. The distinctive clue is milk-like discharge from the nipples when you are not breastfeeding, sometimes with headaches or changes in vision. Causes include certain medications and, less commonly, a benign pituitary growth. A blood test identifies it.

10. Breastfeeding

Periods often stay away for many months while you are breastfeeding, particularly with frequent feeding. This is normal and expected. Ovulation returns before your first period, so pregnancy is possible before any bleeding. Take a test if you suspect it, rather than relying on the absence of periods.

11. Perimenopause

Typically from the mid-forties onward, cycles first shorten and then lengthen before stopping altogether, often alongside hot flushes, night sweats and disturbed sleep. This is a normal transition. Periods stopping before the age of 40 is a different situation, called primary ovarian insufficiency, and needs specialist assessment and treatment rather than being assumed to be early menopause.

Less common causes worth knowing about

• Any significant illness, surgery, infection or hospital stay can delay a cycle.

• Shift work, night duty and long-distance travel disrupt cycles through sleep and circadian changes.

• Chronic conditions including poorly controlled diabetes, coeliac disease, chronic kidney or liver disease, and severe anaemia can all affect periods.

• Genital tuberculosis is uncommon but genuinely important in India. It can cause periods to become scanty or stop, and is a recognised cause of infertility. Worth considering if periods have reduced without another explanation, particularly alongside pelvic pain or difficulty conceiving.

• Scarring inside the uterus (Asherman's syndrome) can follow a D&C or uterine infection, and causes periods to become very light or stop.

What tests will a doctor do?

You do not need all of these. Your doctor will choose based on your history.

Take a note of your last few cycle dates to the appointment. A phone tracker or even a rough list makes the consultation far more useful than trying to recall from memory.

When should you see a doctor?

Book an appointment if you have:

• Missed three periods in a row, or six months of no periods if your cycles were already irregular

• Consistently irregular cycles over several months

• A positive pregnancy test, to start antenatal care

• Repeated negative tests with no period for more than about six weeks

• Milk-like discharge from the nipples when you are not breastfeeding

• Increasing facial or body hair, acne, or hair thinning at the scalp

• Hot flushes, night sweats or vaginal dryness before age 40

• Periods that have become much lighter or stopped after a uterine procedure or infection

• Trouble conceiving after a year of trying, or six months if you are over 35

• No period by age 15 or 16, or by age 13 with no other signs of puberty

Seek urgent care if you have:

• Severe one-sided lower abdominal pain, especially with a positive or possible pregnancy

• Shoulder tip pain, faintness or collapse

• Heavy bleeding soaking through a pad every hour

• Fever with pelvic pain, or foul-smelling vaginal discharge

• Sudden severe headache with visual changes, alongside irregular periods and nipple discharge

What you can do while you wait

None of these is a treatment, and none will restart a period on demand. They address the causes that are within your control.

• Sleep on a consistent schedule. Disrupted and insufficient sleep genuinely affects cycles

• Eat enough. Under-eating and very restrictive dieting are common and frequently overlooked causes

• Moderate very intense training temporarily if your cycles have stopped since increasing it

• Track your cycles from now, even roughly. It is the most useful thing you can bring to a consultation

• Do not take unlabelled or unbranded preparations to "bring on" a period. Several traditional and over-the-counter products sold for this purpose have unlisted ingredients, and some are unsafe in an undetected early pregnancy

• Do not take hormonal tablets to induce a period without a prescription, and never before a pregnancy test

Frequently asked questions

How late is too late for a period?
A few days is normal. More than a week late is worth a pregnancy test. Three missed cycles in a row needs a doctor.

Can stress alone delay a period?
Yes, and it is one of the most common non-pregnancy causes. Significant stress, illness or disrupted sleep can delay ovulation, which delays the period.

My pregnancy test is negative but I have no period. What now?
Repeat the test after a week with first morning urine. If it is still negative and your period has not come, see a doctor, since thyroid problems, PCOS and raised prolactin are all easily tested for.

Can thyroid problems delay periods?
Yes. Both underactive and overactive thyroid disrupt cycles, and thyroid disorders are common in Indian women. A TSH test is simple and inexpensive.

Is a delayed period a sign of PCOS?
It can be, especially with long or unpredictable cycles, acne, excess facial or body hair, or difficulty losing weight. Diagnosis needs blood tests and usually an ultrasound.

Can I get pregnant if my periods are irregular?
Yes. Irregular cycles make timing harder and may indicate ovulation problems, but conception is still possible. If you are trying and it has been a year, or six months over 35, seek help.

Can I be pregnant while breastfeeding without having had a period?
Yes. Ovulation returns before your first period, so pregnancy is possible before you have any bleeding.

Does emergency contraception affect my cycle?
It commonly does, shifting the next period earlier or later. If it is more than a week late, take a pregnancy test.

Should I take tablets to bring on my period?
Not without a prescription, and never before ruling out pregnancy. Some hormonal medicines are unsafe in early pregnancy, and unbranded preparations sold for this purpose may contain undisclosed ingredients.

Are irregular periods normal for teenagers?
Yes, for the first couple of years after periods begin, while cycles establish. Persistent irregularity beyond that, or no period by 15 or 16, should be assessed.

The bottom line

Take a pregnancy test first, whatever you believe the cause is, because it changes every decision that follows. If it is negative, the usual explanations are stress, weight, exercise, contraception changes, breastfeeding, PCOS or thyroid problems, and most of these are identified with a short conversation and one or two blood tests. Three missed periods in a row, milk-like nipple discharge, or periods stopping before 40 are the situations that need proper assessment rather than waiting it out.

Sources

• NHS, stopped or missed periods, irregular periods, and polycystic ovary syndrome

• American College of Obstetricians and Gynecologists, abnormal uterine bleeding and amenorrhoea guidance

• Royal College of Obstetricians and Gynaecologists, polycystic ovary syndrome and premature ovarian insufficiency

• Endocrine Society, clinical practice guidance on hyperprolactinaemia

• World Health Organization, family planning and contraception guidance

• Indian Council of Medical Research and Ministry of Health and Family Welfare, guidance on thyroid disorders, anaemia and reproductive health

• Federation of Obstetric and Gynaecological Societies of India, good clinical practice recommendations

This article is for general information and is not a substitute for medical advice. Seek urgent care for severe one-sided abdominal pain, shoulder tip pain, faintness, or heavy bleeding.