Periods – owning your cycle

  • At a glance

    • Periods are a normal part of puberty. They usually start between the ages of nine and 15, but everyone is different.
    • Periods usually happen once a month and last two to seven days.
    • It’s common for periods to be irregular during the first three years.
    • Cramps, mood changes, and tiredness are common symptoms of periods.
    • If you are worried about pain or any other symptoms related to your period, speak to your doctor.

    Read the parent fact sheet

    What are periods?

    A period, or menstruation, is a natural part of growing up. It’s when blood and tissue from the uterus leave the body through the vagina. Periods usually happen once a month and are a sign your body is maturing. They are nothing to be ashamed of.

    Most periods last between two and seven days, but some people might have a shorter period, and others might have a longer one. The amount of blood lost is different for everyone, but it's usually between 20 and 90ml (mililitres) or about one to five tablespoons.

    When do periods usually start?

    Most people get their first period between the ages of nine and 15; the average age is around 12 years.

    Signs your period might start soon are:

    • Developing breasts
    • Growing pubic or underarm hair
    • Getting discharge from the vagina (clear or white fluid).

    Some things can affect when your period first starts, like your genetics, weight, diet, the amount of exercise you do and how stressed you are.

    It’s a good idea to speak to your local doctor (general practitioner or ‘GP’) if you:

    • grew breasts before age seven
    • haven't had a period by the time you turn 15
    • haven't shown other signs of puberty like growing body hair by age 13.

    Why do periods happen?

    Your menstrual cycle

    The menstrual cycle is your body’s way of preparing for a possible pregnancy. As hormone levels increase, the lining of your uterus (womb) thickens – this is the organ where a baby can grow. About halfway through the month, your ovaries release an egg in a process called ‘ovulation.’ If this egg gets ‘fertilised’ by sperm, you might get pregnant. But if you don't get pregnant, your hormone levels fall, which makes your uterus lining break down and shed. This is a period.

    A full menstrual cycle is the time from the first day of one period to the first day of the next period. The average cycle is 28 days long, but it can range from 21 to 45 days – especially in the first few years of getting periods.

    Tracking menstrual cycles

    Tracking your cycle can help you understand your body's patterns and prepare for your period. You can use a calendar, diary or period-tracking app on your phone to note the start and end dates of your period, flow intensity, and any symptoms you have.

    When should I be worried that my period hasn’t come?

    You should think about seeing your GP if:

    • you haven’t had your first period by age 15.
    • it has been more than three months since your last period, you are not pregnant, and there is no clear reason.
    • you had regular periods, but the periods suddenly stopped or got very irregular.
    • you have other symptoms like acne or excess hair growth.
    • you are sexually active, and your period is late or doesn’t come at all. It’s a good idea to do a pregnancy test as well, even if you have been using protection.

    Common period symptoms

    Getting your period is not just about bleeding – it can come with other physical and emotional changes. This is because of the rise and fall of hormones in your body during your menstrual cycle.

    Here are some symptoms you might notice:

    Physical symptoms

    • Cramps (pain or tightness in the lower belly or back)
    • Bloating (feeling puffy or swollen, especially around your stomach)
    • Tender breasts
    • Aches and pains
    • Headaches or migraines
    • Nausea and vomiting
    • Fatigue (feeling more tired than usual)
    • Digestive changes like constipation or diarrhoea
    • Pimples and acne breakouts 
    • Feeling dizzy and faint
    • Other health problems, like asthma or chronic fatigue, might get worse.

    Emotional symptoms

    • Feeling more sensitive or moody
    • Getting irritated easily
    • Feeling sad, down or anxious
    • Trouble focusing
    • Problems sleeping.

    For some people, these physical and emotional symptoms start a few days before a period. This group of symptoms is called premenstrual syndrome (PMS); it usually goes away once the period starts or ends.

    Pain during your period

    Mild to moderate cramps are common with periods – especially in the first few days. They usually feel like a dull ache or throbbing in your lower belly, back or even your thighs. Cramps happen because your uterus tightens to help push out the blood and tissue.

    If you feel pain during your period that affects your everyday life, it’s a good idea to speak with your GP or another health worker. You know your body best.

    When to get help

    • Your pain is so bad that you can't go to school or get out of bed.
    • Over-the-counter pain medicine like ibuprofen, naproxen or mefenamic acid doesn't help your pain, nausea or dizziness.
    • A heat pack, rest or gentle exercise don't help your pain.
    • Your cramps make you very nauseated, and/or you are vomiting a lot, and over-the-counter medicine doesn't help.
    • You feel dizzy and have fainted or almost fainted, and over-the-counter medicine doesn't help.
    • Your period seems extremely heavy.
    • Your period symptoms get worse over time.

    Period products

    There are many different products to help you manage your periods. The right ones for you depend on your body and lifestyle.

    No matter which period products you use, it’s important to change them regularly. This will stop leaks and help you maintain good hygiene.

    Period products on blue background

    Figure one: Mix of different period products, including a tampon (top left), menstrual cup (bottom left) and pads.

    What are they? How do they work? Pros Cons

    Pads

    Hand holding sanitary pad

    Pads (also called sanitary pads or menstrual pads) are strips that stick to the inside of underwear, catching and absorbing period blood. Pads absorb period blood when it comes out.
    • Easy to use (great for beginners).
    • Lots of different sizes and thicknesses.
    • No internal insertion.
    • Sold almost everywhere.
    • Might feel bulky.
    • Can move around if not stuck properly.
    • Can leak during a heavy flow if not thick or absorbent enough.
    • Not suitable for swimming.

    Tampons

    Hand holding tampon on brown background

    Tampons are small, tube-shaped products inserted into the vagina to soak up period blood from the inside. Tampons are made of soft, absorbent material like cotton and expand as they soak up blood. They have a string that stays outside the body for easy removal.
    • Great for sports and swimming.
    • Less bulky than pads.
    • No feeling of wetness.
    • Lots of different sizes and types – some with applicators to help insertion.
    • Needs to be put in properly to stop leakage.
    • Might not be comfortable, depending on the body.
    • Very small risk of Toxic Shock Syndrome (TSS) if left in too long (always change every four to eight hours).

    Period underwear

    Orange period underwear on pink background

    Period underwear looks and feels like regular underwear but has extra fabric layers to absorb period blood. Period underwear soaks up blood like a pad.
    • Reusable and eco-friendly.
    • Super comfortable – feels like regular underwear.
    • No need to change throughout the day for a light to moderate flow.
    • Can be worn alone (for a light or moderate flow) or as backup protection with other period products.
    • More expensive upfront.
    • Need to be washed and dried properly.
    • Might not be absorbent enough for a very heavy flow.

    Menstrual cups

    Hand holding menstrual cup

    A menstrual cup is a small, flexible silicone or rubber cup inserted into the vagina. It collects blood rather than absorbing it. A menstrual cup sits inside the vagina and forms a seal so blood doesn’t leak out. To insert, the cup is folded up; it opens inside the vagina and collects blood.
    • Long-lasting and reusable.
    • Good for the environment and cost-effective over time.
    • Can be worn for up to 12 hours, depending on flow.
    • Takes practice to insert and remove.
    • Might feel daunting to use at first.
    • Needs to be cleaned well between uses.
    • Might get stuck and need to be removed by a doctor.

    Which period products are right for you?

    Here are a few things to think about when deciding which products to use:

    • Comfort: What feels comfortable will depend on your body. If you are not sure, start with pads and try other options over time.
    • Lifestyle: Are you active? Do you play sports? If so, tampons, menstrual cups or period underwear might be a better fit.
    • Environmental impact: Reusable options like menstrual cups and period underwear create less waste.
    • Cost: Reusable options cost more at first, but they will save you money in the long term.
    • Flow level: If you have a heavier flow, you might need to combine products or use super-absorbent versions.

    Many people mix and match period products. For example, they use pads at night, tampons during the day, or pair period underwear with a tampon for extra protection.

    Don’t be afraid to try a few products until you find what works for you. Everyone’s body is different, and it’s normal to take time to figure out your period routine.

    Things you might be wondering

    Do I need to take iron supplements when I get my period?

    Most people don’t need iron supplements during their period, but it depends on your body and diet. When you get your period, you lose a small amount of blood and, with it, a little iron. You can usually make up for this by eating iron-rich foods like red meat, chicken, fish, beans, lentils, tofu or fortified cereals. Eating vitamin C-rich foods like oranges, strawberries, or tomatoes can help your body absorb iron better.

    You might need extra iron if your periods are very heavy (soaking through a pad or tampon every hour), you feel tired all the time, or you get dizzy or out of breath easily. You should talk to your GP before starting any supplements, as they might cause side effects.

    My period does not come at the same time each month. Is this normal?

    It’s normal for your period to come at different times each month – especially when you have just started getting it. This is because your body is still getting used to new hormone patterns. Your period might come early, late, or not come at all for a month. Other things that can impact how regular your periods are include stress, illness, major weight changes or too much exercise. Over time, most people's cycles become more regular.

    If your period used to be regular but has changed, you haven't had a period for several months, or you often get your period more than once every 21 days, speak with your GP for advice.

    Why do I get other side effects during my period if the change is happening in my uterus?

    Hormones are chemical messengers in the body. Changing hormone levels make your uterus thicken, thin and break down, causing a period. But they also send messages to other parts of your body. That’s why you might get headaches, mood swings, nausea or other symptoms during your period.

    What is menstrual suppression?

    Menstrual suppression means using medicine (usually hormones) to change your periods. It can make your periods lighter, less frequent, or stop them for a while. Medicine can also help people who find periods very hard to manage.

    It’s safe to use period-suppressing medicine if you feel comfortable and your GP (or another health worker) agrees it’s right for you. The blood doesn't 'build up' or cause harm, and it won’t make it harder for you to have babies later in life (it won’t affect your fertility) if you choose to. Remember that pregnant people don’t usually get a period for nine months.

    There are many ways to suppress periods, like the pill, hormonal intrauterine devices (IUDs), an injection, or an implant. Everyone is different, so speak with your child and their doctor about what may work best.

    Is it common to feel emotional when you have your period?

    It’s common to feel emotional during your period. Hormones like oestrogen and progesterone rise and fall throughout your cycle, which might affect your mood. Many people feel more sensitive, sad, anxious, or irritable in the days before their period starts.

    If your emotions feel very intense or don’t go away after your period finishes, it’s a good idea to speak with your GP or a mental health worker, like a psychologist. They will be able to support you and answer any questions or worries you have.

    What is endometriosis?

    Endometriosis is a condition where tissue like the uterus lining grows outside the uterus. The uterus lining changes during each menstrual cycle. It gets thicker and thinner before the excess comes out as a period. For people with endometriosis, some excess lining attaches and grows in places it doesn’t belong, and blood gets trapped. This can cause pain in some people.

    Period pain is not always a sign of endometriosis. Many people with the condition don’t get any symptoms at all, so diagnosing endometriosis can be hard. Speak to your GP if your period is affecting your everyday life or if you are worried for any other reason.

    What is polycystic ovarian syndrome (PCOS)?

    Polycystic ovarian syndrome (PCOS) is a condition caused by hormones. Some young people with PCOS will get acne, irregular periods, excess body hair and extra fluid-filled sacs (follicles) on their ovaries. But because these are all common changes during puberty, it can be tricky to tell if these symptoms are signs of PCOS. If you are unsure, speak to your GP.

    Can the pill cause PCOS?

    The pill does not cause PCOS. This is a common myth, but there is no evidence to support it. The pill does the job of the ovaries by giving your body a steady supply of some hormones. When you stop taking the pill, your body goes back to making its own hormones. This might make side effects like irregular periods and acne come back. You can always speak to your GP for more information.

    Helpful links

      

    Developed by The Royal Children’s Hospital (RCH); medical review by the Adolescent Medicine department, with input from the Gynaecology department. Created with advice from the RCH Health Literacy Youth Advisory Committee.

    Reviewed August 2025.

    Speak with a doctor for up-to-date and personalised medical advice.


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    Disclaimer

    This information is designed to help you have conversations with your doctor or health care professionals. It is not intended to replace personal medical advice. The authors of these fact sheets have worked hard to make sure the information is accurate, up-to-date and easy to understand. The Royal Children’s Hospital Melbourne does not accept responsibility for any content inaccuracies, information seen as misleading, or the success of any treatments explained in these fact sheets. Information in these fact sheets is updated regularly. If you download or print the fact sheet, the responsibility is on you, the user, to make sure you are reading the most up-to-date version.

    Updated July 2025