Normal Menstrual Cycle Duration: How Long Should Your Period Last?

How long should a period and a cycle last?

Many girls and women wonder whether their period is "normal". Is it too long, too short, too heavy, too late? This guide explains what a normal cycle looks like, how it changes through life, how to track it, and when to see a doctor. Whether you are a girl starting your periods, a parent, or someone who wants to understand her body better, it is for you.

What is a period?

A period is when the lining of the womb (uterus) sheds and leaves the body through the vagina. Each month, hormones thicken this lining in case a pregnancy begins. If it does not, the lining is not needed, and it sheds as a mix of blood, mucus and tissue. Periods usually start between the ages of 9 and 15 and continue until menopause.

What is a normal cycle length?

Count your cycle from the first day of one period to the first day of the next.

• For adults, a cycle between 21 and 35 days is normal. The often-quoted 28 days is only an average.
• In the first few years after periods start, cycles of up to 45 days, and some irregular months, are common.
• Bleeding usually lasts two to seven days.

What matters most is your own usual pattern. If your cycle is often shorter or longer than this, or suddenly changes, see a doctor.

The four phases of the cycle

• Menstrual phase: your period. Hormone levels are low and the womb lining sheds.
• Follicular phase: from the first day of your period to ovulation. An egg matures in the ovary and the womb lining builds up again.
• Ovulation: the ovary releases an egg, usually about 12 to 16 days before the next period. In a 28-day cycle, that is around day 14.
• Luteal phase: after ovulation. Progesterone keeps the lining ready. If there is no pregnancy, hormone levels fall and the next period begins.

When do periods start?

Most girls get their first period between 9 and 15, often about two years after their breasts start to develop. Family history, body weight, nutrition, health and stress can all affect the timing. See a doctor if breasts start to develop before 8, the first period comes before 10, or periods have not started by 15.

How your period changes through life

• Teenage years: cycles are often irregular while the body settles. This usually improves with time.
• Adult years: cycles are usually more regular, though stress, illness, travel and weight change can upset them.
• Perimenopause: in the years before menopause, usually from the mid-40s, periods may become irregular, heavier or lighter. Hot flushes, night sweats and mood changes are common.
• Menopause: periods stop. Menopause usually comes between the mid-40s and early 50s. Any bleeding after menopause needs a doctor's check.

How to track your cycle

Mark the first and last day of each period on a calendar, in a diary or in a notes app. Note any pain, heavy days or mood changes too. After a few months you will know your usual pattern, and you can tell a doctor clearly if it changes.

Our period and ovulation calculator estimates your next period and your likely fertile days. It gives an estimate only. It is not a reliable way to avoid pregnancy. If you want to avoid pregnancy, talk to a doctor about contraception.

Before your period: PMS

In the days before a period, many people feel bloated, tired or moody, or have sore breasts or food cravings. These are signs of premenstrual syndrome (PMS), caused by changing hormones. They usually ease once bleeding starts. If they are severe, or affect your daily life, see a doctor.

Easing period pain at home

• A hot water bottle or warm towel on your lower belly.
• Gentle movement: walking, stretching or simple yoga.
• Rest, warm drinks, and regular meals.

Ask a doctor or pharmacist which pain medicine is safe for you. Pain that does not get better with these steps, or that keeps you away from school or work, needs a doctor.

Common conditions that affect periods

• PCOS (polycystic ovary syndrome): a hormonal condition that causes irregular periods and raised male-type hormones, with acne or extra hair. Many people with PCOS have no cysts on their ovaries.
• Endometriosis: tissue like the womb lining grows outside the womb. It often causes severe period pain, and pain during sex.
• Fibroids: non-cancerous growths in the womb that can cause heavy or long periods.
• Thyroid problems: can make periods heavier, lighter or irregular.

Each of these can be treated. A doctor can help.

Food and your period

Losing blood each month uses up iron. Eat iron-rich foods such as dals, rajma, chana, ragi and green leafy vegetables, and eggs, fish or meat if you eat them. A squeeze of lemon or some amla with the meal helps the body absorb the iron. Milk, curd and paneer give calcium.

Myths and facts

• Myth: you should not exercise on your period. Fact: gentle exercise is safe and can ease cramps.
• Myth: period blood is dirty. Fact: it is the lining of the womb. It is not dirty or impure.
• Myth: you cannot get pregnant on your period. Fact: it is less likely, but it can happen, because sperm can live in the body for up to five days.
• Myth: pads, cups or tampons cause infertility. Fact: they do not.

When to see a doctor

• Your cycle is often shorter than 21 days or longer than 35 days.
• Your period lasts more than seven days.
• You soak through a pad every hour or two, or pass large clots.
• Your periods stop for three months and you are not pregnant.
• You bleed between periods, after sex, or after menopause.
• Pain keeps you away from school, college or work.
• Breasts start to develop before 8, the first period comes before 10, or periods have not started by 15.

Have a question about your period? Call our menstrual helpline on 85888 70999. It answers at any hour.

FAQs

What is a normal cycle length?

For adults, 21 to 35 days, counted from the first day of one period to the first day of the next. In the first few years after periods start, up to 45 days is common.

How long should a period last?

Usually two to seven days. If yours often lasts longer than seven days, see a doctor.

How can I track my cycle?

Note the first day of each period on a calendar or in an app, along with any symptoms. Our period and ovulation calculator can estimate your next period.

Can a calculator tell me my safe days?

No. A calculator gives an estimate only, and ovulation can shift. It is not a reliable way to avoid pregnancy. Talk to a doctor about contraception.

When should I worry about my cycle?

See a doctor if your cycle is often outside 21 to 35 days, your period lasts more than seven days or is very heavy, your periods stop for three months, or pain affects your daily life.

In short

There is no single "perfect" cycle. Get to know your own pattern, note any changes, and see a doctor when something does not feel right.

About Pinkishe Foundation

Pinkishe Foundation is a specialist implementation organisation for menstrual health. We deliver, reliably, in schools and communities across India. Support our work with a donation.

Learn more

• Period and ovulation calculator
• Menstrual myths and facts
• Test your knowledge: take our menstrual quiz