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Period and the Menstrual Cycle


Period and the Menstrual Cycle

period menstrual cup

The start of your period indicates the start of your menstrual cycle. Each month a woman’s body prepares itself for pregnancy with the lining of the uterus wall (endometrium) thickening in readiness to receive a fertilised egg. If the egg is not fertilised, the uterine wall is shed. During a woman’s period, menstrual fluid made up of blood, tissue and fluid which made up the endometrium, passes from the uterus through the opening of the cervix, through the vagina and out of the body.

The average menstrual cycle is 28 days. Your period can last between 3 and 8 days but usually lasts about 5 days.  Bleeding tends to be heaviest for the first couple of days when the blood will be red.  On days when it is lighter your period is likely to be pink or brown.

During your period you can expect to lose about 5 to 12 teaspoons of blood, although some women can bleed more heavily than this.

When do periods start?

Girls will have their first period around the age of 12, about 2 years after the first signs of puberty. Some girls can experience puberty a lot earlier or later and can start their period as early as 8 or as late as 18.  If your periods haven’t started by the age of 16, make an appointment to see your doctor as there maybe an underlying issue causing puberty to be delayed.

Puberty typically starts at around 9-10 years with the first signs of breast development. Generally, girls can expect their first period 2-3 years after this and usually about 1 year after getting white vaginal discharge.

Most girls can expect their periods to be irregular for a couple of years before experiencing regular periods, usually between the ages of 16 and 18.

What sanitary product should I use?

There are several types of sanitary product which absorb or collect blood and menstrual fluid during your period. Sanitary pads, tampons and menstrual cups are all suitable for girls just starting their periods although tampons and cups can take a little getting use to, so you may want to start with pads.

Sanitary pads are available it both disposable and reusable forms.  Both types are strips of absorbent padding which attach to your underwear where they can soak up your menstrual blood. Disposable options are sold in all pharmacies, supermarkets, and convenience stores and come in varying sizes depending on your flow. Biodegradable towels are available in a few of the larger supermarkets and pharmacy’s but are more easily found on line. Reusable sanitary pads are a lot less common, mainly due to demand as women generally prefer the convenience of disposable sanitary wear.  If, however, you are concerned by the environmental impact of disposable plastics (some disposable towels can contain up to 4 plastic bags worth of plastic) you might like to consider reusable towels. Also, many women using reusables comment on there comfort and how easy they are to use. You can find a good selection of reusable products on-line at websites such as No More Taboo, Earth wise girls, Honour Your Flow and Cheeky Wipes.

Tampons are small tubes of cotton wool which you insert into your vagina.  The blood from your menstrual flow is absorbed before it leaves your body.  Your vaginal holds it in place while it expands inside you as it soaks up the blood.  There is a string at one end of the tampon which you pull to remove it.  Tampons should be changed regularly (about 4 times a day).  Tampons come in a selection of sizes depending on your flow. Always read the instruction leaflet that comes with the tampons. The vast majority of tampons sold are not biodegradable. If you would like to consider a more eco friendly options which are also likely to chemical free look online or in some of the larger pharmacies or supermarkets.

Menstrual cups are made from silicone and are placed inside your vagina.  Once inserted, the cup will spring open and rest against the walls of your vagina. It forms a seal to prevent leaks and the blood then simply drips into the cup.  As a cup can collect up to 3 times more blood than a tampon, you should only need to empty it every 12 hours.  The cup is easily removed when it can be emptied, rinsed and reused. When you have finished using it, it can be sterilised and stored for reuse. Not only are they eco friendly, they can be reused for up to 10 years, they are a huge money saving option.

When during my cycle am I most likely to fall pregnant?

Your most fertile time is during ovulation, when an egg is released from one of two ovaries and travels through one of the fallopian tubes to the uterus.  If you have sexual intercourse with a man at this time and his sperm fertilizes the egg, you will become pregnant. Ovulation occurs 12 to 14 days before the start of your next period.  Sperm can survive inside a woman’s body for up to 4 days so if you have sex several days before ovulating it is still possible to fall pregnant.  Please follow these links for more information on pregnancy and family planning.

 Period Problems

Your period can often change by becoming lighter or heavier, longer or shorter.  This does not necessarily mean something is wrong.  If you are concerned about any changes, speak to your GP, practice nurse or nearest women’s clinic where you can receive help and advice.

Women can experience a variety of problems related to their periods such as:-

Period pain

Pain during your period is common and can be felt as muscle cramps in the tummy, back and thighs.  Some months you may have little or no discomfort while other months you may experience a lot of pain.  Pain can also be felt as intense spasms or as a more constant, dull pain. This pain is often caused by the wall of the womb contracting during your period as it encourages the womb lining to shed. Pain can also be caused by an underlying condition such as endometriosis, fibroids, pelvic inflammatory disease and adenomyosis.

Heavy periods

Average blood loss can vary from woman to woman so a normal period for one woman maybe heavy for another. An indication of a heavy bleed maybe if you find yourself needing to change your pad or tampon more often or having to use both together.  Heavy bleeding can be very distressing for a woman and disrupt everyday life. It may be caused by an underlying medical condition or from some medicines. If you have noticed your period becoming abnormally heavy for what is normal to you or are concerned, speak to your GP, practice nurse or nearest women’s clinic where you can receive help and advice.

Your GP may suggest the combined oral contraceptive pill to ease period pain and treat heavy periods.  The pill can be an effective treatment as it thins the womb lining.  A thinner womb lining means the womb doesn’t have to contract as much when shedding the lining of the uterus wall.  This also effectively makes your period lighter.

Irregular periods

The average menstrual cycle last 28 days however, your own cycle could be a little longer or shorter than this. You would normally expect a regular cycle of a similar length of time by the time you are 18 and you have been having your period for a couple of years or more.  If you do experience irregular periods this does not have to indicate a problem, but if you have gone through puberty and are experiencing any or the follow problems, see your GP:

  • Periods suddenly become irregular and you’re under 45
  • Periods more often then every 21 days or less often than every 35 days
  • Periods last longer than 7 days
  • There’s more than 20 days difference between your longest and shortest cycle
  • You are struggling to get pregnant

In some cases, your GP may recommend the combined oral contraceptive pill to regulate your period.  If, however, they feel there maybe an underlying health issue that needs to investigated, you should expect to be referred to a specialist gynaecologist.

Stopped or missed periods

There are a number of reasons why a woman may miss her period or why her periods may stop:

If you are concerned, make an appointment to see your GP.

Premenstrual Syndrome (PMS) and Premenstrual Tension (PMT)

Throughout your monthly cycle your body’s hormone levels change which can cause both emotional and physical changes, particularly in the 7-14 days prior to your period.  This is known as premenstrual syndrome (PMS) or premenstrual tension (PMT). Women can experience mild or severe symptoms which may also vary in severity from month to month.

Some typical symptoms are:-

  • Tender swollen breasts
  • Headaches
  • Stomach cramps
  • Feeling irritable
  • Stomach bloating
  • Backache
  • Acne outbreaks
  • Weight gain
  • Clumsiness
  • Tiredness
  • Tearfulness
  • Food cravings

These symptoms tend to disappear or greatly improve once your period actually starts. For more information on Premenstrual Syndrome (PMS) and Premenstrual Tension (PMT), please follow the link.


Endometriosis is a condition where the cells that are normally found lining the uterus are also found in other areas of the body.  It can cause painful, heavy and irregular period as well as pain when going to the toilet and during or after sex.  For more information about endometriosis, please follow this link.

Ovulation Pain

Some women experience pain when ovulating, up to 2 weeks before their period starts.  This can be a dull or sharp pain felt in the lower abdomen which can last just a few minutes or for a couple of days. Some women can experience a little vaginal bleeding at this time.

Pain relief can be found by soaking in a hot bath or by taking pain killers such as paracetamol or ibuprofen.  If you are in a lot of pain, you can discuss other treatment options with your GP.

Bleeding after Childbirth

After childbirth a woman will experience heavy bleeding known as lochia which can last between two and six weeks. This type of blood loss varies between women, coming out quickly or slowly and evenly. Those who have had a vaginal birth are more likely to have heavier bleeding than those who have had a caesarean section. The colour of the blood will change from bright red in the first few days then becoming lighter and waterier.  You can also expect to see small clots.

You will need to use thick sanitary pads and can move to regular pads once the flow slows.  Due to the risk of infection you should not use tampons for the first six weeks after giving birth.

Seek advice from your GP or midwife if you notice any of the following: –

  • Your bleed smells unpleasant
  • The bleeding is still heavy and bright red after the first week
  • You have lower tummy pain
  • You get a fever or experience chills

If you experience very heavy bleeding which soaks through more than 1 pad in an hour, call an ambulance as this may indicate a postpartum haemorrhage.  This can be caused by a piece of placenta still inside your womb which will need to be treated with antibiotics or an operation to remove it.

Delaying Periods

Although periods are a natural and normal part of being a woman there may be times when you wish to delay a period. This could be due to an up and coming holiday or special event when it would be more convenient to delay your period until a later date.  There is no guaranteed way to delay your period but there are a number of ways where it may be possible, such as using the combined oral contraceptive pill, contraceptive vaginal ring or the prescription drug Norethisterone.

For more information on delaying your period please follow this link.