• Help & Advice
  • Find a Service
    Close icon
My Body


A period, also known as menstruation, is the part of the menstrual cycle where blood is shed from the vagina. Girls and people with vaginas will start to have periods between the ages of 8 and 17.

What is a period?

Between the ages of 8 and 17, girls and people with vaginas begin their monthly cycle known as the menstrual cycle. This is what makes pregnancy possible.  

Every month, the ovaries release an egg – this is called ovulation. This egg travels down the fallopian tubes to the uterus, which you might hear being called the ‘womb’.  

At the same time, the lining of the uterus thickens with blood and body tissue – this is to prepare for a pregnancy as the blood and tissue will provide nutrients for a foetus. 

Once an egg has been released, if it not fertilised by a sperm (which is what causes pregnancy) then it is shed through the vagina along with the lining of the womb. This is a period. 

How long do periods last?

Period bleeding will usually last for three to eight days. 

Periods usually happen every four to five weeks, so once a month. However, some people will have a longer or shorter gap between periods. 

Some people might find that the gap between their periods changes – this is called having an irregular cycle or irregular periods. Having an irregular cycle doesn’t mean that there is anything wrong. It’s common for people’s periods to be irregular, happening every few months or skipping a month, when they first start having them, then for them to become more regular as they get older. 

Periods continue throughout your life unless you become pregnant or when you reach menopause, which usually happens between the ages of 44 and 56. This is when you stop being able to get pregnant and your periods stop, too. 

If you usually have regular periods and they start becoming irregular without any obvious reason, it’s a good idea to speak to a medical professional. 

How much blood is normal for a period?

It’s usually about one to five tablespoons’ worth of period blood that leaves your body during your period (around 20-90ml) – though it sometimes feels like more than that! 

Often when people talk about periods, they will describe them as being ‘light’ if there is only a little bit of blood or ‘heavy’ if there is lots of blood.

Most people find that their period is light at the very start and then again at the end, but that it gets heavier during the middle. This means they might need to use different products on different days of their period to help them manage it. Find out about period products

It’s helpful to learn what a normal period looks and feels like for you so you can spot any changes, which might mean something needs to be checked by a doctor. And remember – lots of things can affect how light or heavy your period is, including contraception

What does a period look like?

Like with a lot of things to do with our bodies, everyone’s period will be a bit different. But there are some things that lots of people will notice and wonder if it’s normal. 

It’s totally normal if: 

  • Period blood isn’t red – it can be any colour from bright pink to red to brown. 
  • The blood changes during your period, so it might look different at the start compared to the end of your period. 
  • The blood is watery or quite thick, or the consistency seems to change from one day to the next.  
  • You see ‘lumps’ in the blood – these are blood clots and are nothing to worry about. 
  • Bleeding stops and starts – you may bleed for a few hours, and then stop for a few hours. Or you may stop bleeding all through the night, or all through one day. 
  • Sometimes your period is a bit lighter or heavier than normal. 
  • You see some spots of blood a few days before or a few days after your period. 
  • You think it’s your period is over but then there’s one final wave! 

If you have one or more of the above, chances are that nothing is wrong. But if you notice that you’ve had one or two periods that are really out of the norm for you then it’s worth checking with a medical professional. 

The side effects of periods and PMS

Your period is started by a drop in hormones (chemicals produced by the body) and the walls of the uterus contracting and tightening.  

In the days (or possibly weeks) leading up to your period, you may experience some uncomfortable symptoms, this is called premenstrual syndrome (PMS) or premenstrual tension (PMT). 

No one knows exactly what causes PMS, but it’s thought to be linked to the drop in hormone levels.   

PMS can have different symptoms:


  • Breast pain
  • Cramps
  • Muscle pain
  • Spots
  • An upset stomach
  • Diarrhoea or constipation


  • Mood swings
  • Feeling more irritable
  • Difficulty concentrating
  • Anxiety
  • Less sociable
  • Difficulty sleeping

You might have none, some, or all of these symptoms. Sometimes the symptoms last through your period, or you may find they disappear when you start to bleed. 

PMS isn’t fun, but it shouldn’t interfere too much with your day-to-day life. If you find that you are struggling, it’s important to look for help. This could be from a friend, family member, trusted teacher or colleague, or a medical professional like your doctor or someone at your local sexual health service

During your period, you might experience cramps, these are when happens when the muscular walls of the uterus tighten (contract) to help the lining shred. It’s normal to feel a bit of pain and discomfort from cramps, but again they shouldn’t stop you living your life normally and there are lots of things you can try to help make them better. 

Starting your period

You might be nervous to start your period, it can feel like a big change. But there’s no need to be worried; managing your menstrual cycle and period will become a natural part of your life.  

When will it start?

The average age to start getting periods is 12, but most people’s start between the ages of 8 and 17.  

You can start your period at any time or anywhere. If you’re nearing the age of starting your period (around age 12), it might be a good idea to talk to your parent or carer about having some period products ready at home ready for when it happens. You could also carry some in your bag and make sure you know where to access them at school in case you need to. 

If you’re worried about using period products like pads, tampons or menstrual cups, having a conversation about how to use them with a trusted adult or experienced friend/sibling might make it feel less scary and you’ll be more prepared when it does happen. 

You might not notice straight away when your period starts, and most people will only see it when they go to the toilet. Some people might see discharge that is a slightly pink colour the day before their period, while other people get no warning and will just see the blood.  

What should I do?

You might feel embarrassed to talk about it, but it’s really important you tell the person you live with that you’ve started your period, whether that’s a parent, carer or older sibling. They can make sure you have period products; help you understand how to use them and answer any questions you might have.  

Period products stop the blood leaking onto your clothes. There are lots of different types that you can use including pads, tampons, menstrual cups and period pants. If you’re unsure, pads are the easiest to use especially for your first period.  

What if I’m out when my period starts?

If you’re out and not at home when it happens, don’t panic! It’s completely normal and half the population experience it.  

If you have period products on you, then great! Head to a bathroom or public toilet.  

If you don’t, don’t worry there are lots of places you can get some: 

  1. Ask a friend – if you know someone who has started their period, they might have some period products on them that they could give you.  
  2. Get free products from your school – If you’re in school at the time, your school will likely have period products they can give you. If you don’t know where these are kept or who to go to, it’s a good idea to go to the school’s reception or go to the school nurse.  
  3. Head to a shop – most supermarkets sell period products in the toiletries aisle 
  4. Buy products at public toilets – lots of public toilets have vending machines for pads and tampons. These are normally about £1 each but will get you out of a sticky spot until you can get some.  
  5. Ask – you know how sometimes when you’re in the loo you might ask the person in the cubicle next to you if they have any toilet paper? If it feels safe, you can also ask anyone in the toilets if they have a spare pad or tampon. Most people will be more than happy to help you out if they can. 
  6. If it’s a real emergency and you can’t get your hands on any period products, you can temporarily use something else like a clean sock or toilet paper wrapped around your underwear. This isn’t recommended, but it can absorb some of the blood whilst you locate a pad or tampon. If your bleeding is light, which is likely at the very start, you will probably be ok with just your underwear for an hour or so. 
What happens if I leak?

First things first, don’t be embarrassed. It’s completely normal and pretty much everyone who has a period has leaked onto their clothes at some point.  

It might be that your pad has moved, you forgot to change your pad or tampon or your menstrual cup or tampon wasn’t inserted properly. With time, this gets easier and leakages are less likely, although can still happen.  

If you are worried about leaking, here’s a few things you can try: 

  • Use menstrual cups and period pants – these can hold more blood than other period products meaning you don’t need to change them as often 
  • Double up on products – for example use a menstrual cup and a pad  
  • Wear dark clothing on period days so any leaks won’t be noticeable until you’re more confident with using period products 
  • Keep a spare pair of underwear with you during your period – that way, if you do have a leak when you’re out and about, you can change. 

When to see a doctor

Everyone’s period is different. It’s good to pay attention to what is normal for you and to notice if anything changes.  If you notice anything outside the normal for you, it’s a good idea to tell someone or speak to your GP. 

Some things to look out for are: 

  • Blood clots measuring over 2.5cm, or noticeably more clots than usual  
  • Obviously lighter or heavier periods for several cycles 
  • Pain during your period that painkillers don’t help with and affects your daily life 
  • Irregular periods – if your periods are still irregular after two years of having them, or have suddenly become irregular 

There might be nothing wrong but it’s a good idea to check with a doctor.  

LGBT+ and periods

If your gender is different to the one given you at birth, you may find periods triggering or uncomfortable. For many transgender people, periods directly challenge their identity and gender. This can make it difficult to:  

  • Deal with period blood 
  • Insert something into their vagina 
  • Wear a chest binder when breasts are swollen or tender 
  • Use the men’s toilets during their period, particularly when it comes to throwing away used pads and tampons without sanitary bins  

There are things that can make it easier: 

  • Some companies do period boxers 
  • Some period products, like period pants and menstrual cups, hold more blood meaning they don’t need changing as often 
  • Some contraception methods can stop your period, but this isn’t advisable if you’re looking at taking, or are currently taking, testosterone.  

In a similar way, if someone doesn’t have a period this can challenge their identity. For example, transwomen or women who have had a hysterectomy (removal of the uterus by surgery) may struggle with their identity as a woman.  

For this reason, some people choose to use the moon’s cycle (which is around 27 days) to plan a time for rest and reflection that would normally take place during a period.  

Period FAQs

How often should I change a tampon?

It is important to use a tampon that is the right absorbency for you. Always choose a tampon with the lowest absorbency necessary for your blood flow.

There is a very small risk of Toxic Shock Syndrome (TSS) with tampon use. This is extremely rare but using the lowest absorbency tampon for your flow and not leaving your tampon in for longer than needed reduces this risk.

If your tampon leaks, then you have either left it in too long, or you need to try a higher absorbency. If your tampon doesn’t come out easily, or it feels uncomfortable when you pull it out, this can mean that it hasn’t soaked enough blood yet, so leave it in a bit longer. If your tampon is still difficult to remove after four to six hours, switch to using a lower absorbency tampon.

Aim to take a tampon out every four to six hours, depending on your flow. It is safe to wear a tampon overnight, but it’s important to take it out as soon as you wake up in the morning.

Are ‘period poos’ a real thing?

You might notice that in the days leading up to your period or during your period you may poo more or have diarrhea. This is completely normal! As your body is preparing to shed the lining of your uterus it produces prostaglandins which cause your uterus to contract but also cause your stool to move quicker through your intestines.

It’s also normal to experience the opposite, constipation.

Focusing on your diet is a great way to help with these symptoms but if this is affecting your ability to go about your daily life, you should speak to your GP to get extra support. It might be that using hormonal contraception might be useful for you.

Is it safe to have sex on my period?

It’s perfectly safe from a health point of view to have sex on your period – although you can still get pregnant as a result! So make sure to use contraception, if you don’t want to get pregnant, and to use condoms to protect against sexually transmitted infections. Period sex can sometimes get messy, too, because of the blood – so think about putting down an old towel first to soak up any escaping fluids!

Technically, you are more likely to become pregnant at a certain time of the month, during ovulation, but it’s impossible to tell when you will next ovulate. This is because your menstrual cycle can vary from month to month. Also, sperm can live in your body for up to seven days, which means it is high risk to have unprotected sex up to seven days before ovulation. Always use a method of contraception, even when you are on your period.

  • On this page

    Other Stuff you might find useful…


    Period Survival Guide

    My Body

    Period products

    My Body

    Period FAQs

    My Body

    Love your vulva

    Vaginas & Vulvas

    Breasts and Chests

    My Body


    My Body
    Our friendly staff are here to help
    Find a Service near you

    100% free & confidential