Missed or late periods

A period is late when it does not start around the time you expected. It is missed when an expected period does not happen at all. Menstrual cycles do not always follow an exact schedule, so a single late period can be part of normal variation.

The medical term for having no periods is amenorrhea. Primary amenorrhea means periods have not started by the expected age. Secondary amenorrhea means periods started in the past but have now stopped.

Pregnancy is an important possibility if sperm could have entered the vagina, even if contraception was used. A home pregnancy test is usually the best first step. Testing too early can give a negative result, so follow the test instructions and repeat it if your period still does not come.

Often, the only change is that menstrual bleeding does not begin when expected. You may still have symptoms that usually happen before your period, such as mild cramps, bloating, breast tenderness, acne, or mood changes.

Other symptoms can offer clues about the cause. These may include:

• Nausea, breast changes, or tiredness with pregnancy
• Hot flushes or night sweats during perimenopause
• Weight change, stress, or increased exercise
• New facial hair, acne, or scalp hair thinning
• Headaches, vision changes, or milky nipple discharge
• Pelvic pain or unusual vaginal bleeding

These symptoms do not confirm a particular condition. They help a healthcare professional decide what checks may be useful.

Pregnancy is a common reason for a missed period. No contraceptive method prevents every pregnancy, and irregular cycles can make pregnancy timing difficult to judge.

Stress and routine changes can affect the brain signals that control ovulation, which is the release of an egg. Travel, disrupted sleep, illness, grief, and major emotional strain may delay a period.

Weight, eating, and exercise changes can also interrupt ovulation. This is more likely with rapid weight loss, not eating enough for your body’s needs, or intense exercise. It can happen at any body size.

Hormonal contraception may make bleeding lighter, irregular, or absent. This can happen with some pills, injections, implants, and hormonal intrauterine devices. Missing doses or using a method late can also change bleeding and may reduce pregnancy protection.

Life stage changes are another common explanation. Periods can be irregular during the first few years after they begin. They can also become less predictable during perimenopause, the transition before menopause.

Less common causes include polycystic ovary syndrome, often called PCOS; thyroid conditions; raised prolactin, a hormone involved in milk production; some medicines; and conditions affecting the ovaries, uterus, or hormone-control centres in the brain.

A missed period with pain or bleeding can occasionally be linked to an ectopic pregnancy, where a pregnancy develops outside the uterus. This needs prompt medical assessment.

Seek emergency help if pregnancy is possible and you have severe or worsening lower abdominal pain, fainting, marked dizziness, shoulder-tip pain, difficulty breathing, or heavy vaginal bleeding. These symptoms may need urgent treatment.

Arrange same-day medical advice if you have a positive pregnancy test with one-sided pelvic pain or vaginal bleeding, even if the symptoms are not severe.

Book a routine appointment if:

• You have missed three periods in a row and are not pregnant
• Your periods repeatedly become much less predictable
• You have new facial hair, severe acne, nipple discharge, hot flushes, or major weight change
• Periods have not started by age 15
• The change began after starting a medicine
• You are worried about fertility or the effect on your bone health

A single late period without concerning symptoms can usually be monitored at home.

A healthcare professional may ask about your usual cycle, sexual activity, contraception, pregnancy possibility, medicines, exercise, eating patterns, stress, and other symptoms. It may help to bring period dates or information from a tracking app.

A pregnancy test is commonly the first check. Depending on your situation, you may also be offered blood tests for thyroid function, prolactin, or hormones related to the ovaries and ovulation.

An examination is not always needed. In some cases, an ultrasound may be used to look at the uterus and ovaries. The tests chosen depend on your age, symptoms, medical history, and how long your periods have been absent.

Treatment depends on why the period is late or absent. One isolated late period often does not need treatment.

Keep a record of bleeding, pain, pregnancy test results, medicines, and major changes in stress, food intake, weight, or exercise. If pregnancy is possible, test according to the package instructions. Repeat the test or seek medical advice if it is negative but your period remains absent.

Try to eat regularly, get enough rest, and avoid sudden increases in demanding exercise. If stress is affecting sleep, eating, or daily life, support from someone you trust or a mental health professional may help.

A clinician may adjust contraception or another medicine, treat a thyroid or hormone condition, or discuss treatment for PCOS. If low energy intake or intense exercise is interrupting periods, care may involve nutrition, activity, and emotional support. Do not stop prescribed medicine or start hormone products without medical advice.

A period delayed by short-term stress, illness, or routine changes may return during the next cycle. It can take longer if the cause continues.

Periods may remain light or absent with some hormonal contraceptives. During perimenopause, they may become irregular before stopping. Menopause is generally reached after 12 months without a period when there is no other cause.

Repeatedly absent periods deserve assessment because some underlying causes can affect fertility, bone health, or general health. This is usually a routine appointment unless urgent symptoms are present.

Can I be pregnant after one negative test?

Yes. A test may be negative if it was taken too early or the urine was diluted. Follow the instructions and repeat it after the recommended interval if your period still has not started.

Can stress really delay a period?

Yes. Physical or emotional stress can change the hormone signals that control ovulation. However, pregnancy and other causes should still be considered.

Is it harmful not to bleed while using hormonal contraception?

Not necessarily. Some methods deliberately keep the uterine lining thin, so there is little or no bleeding. Ask for advice if the change is unexpected, pregnancy is possible, or you have pain or other symptoms.

Can I become pregnant while my periods are irregular?

Yes. Irregular or absent bleeding does not always mean ovulation has stopped. Ovulation can happen before the next period, making timing difficult to predict.