Your Menstrual Cycle

Your menstrual cycle is the process your body goes through continuously from the time you get your first period to when you begin menopause (learn more about menopause here). Specifically, your menstrual cycle begins on the first day of one period and lasts until the day before your next period starts. The average menstrual cycle is 28 days, but most women aren't that regular. It's not unusual to have a menstrual cycle as long as 35 days or as short as 22 days.

When you hit puberty (for most women, between the ages of 10 and 16) your body starts to produce varying amounts of different hormones that are responsible for particular changes in your body. During your menstrual cycle, hormone levels change and your ovaries start to develop an egg. Up to 20 follicles start to develop in every cycle, but only one or occasionally two will mature into fully formed eggs ready to be fertilised. Once the egg is released (this process is called ovulation), it travels down your fallopian tubes – the two tubes that connect your ovaries to your womb. Meanwhile, the lining of your uterus (or womb) thickens – this is because your body is anticipating a pregnancy. If an egg and sperm meet, it can lead to fertilisation resulting in a pregnancy (see more below). Unfertilised eggs only survive for about 24 hours after ovulation. Ovulation usually occurs mid-cycle, but it can vary from woman to woman. After that point, the lining of your womb will come away and mix with blood to produce a menstrual period that travels out your vagina.

Your Period

It’s normal for your period to last between one day and eight days, but the average length of a period is four to five days. Normally you lose about 80mls of blood during a period – about 16 teaspoons. If you take the contraceptive pill you may find your periods are lighter and shorter than the periods you had before taking it. That’s because the pill prevents your ovaries from releasing an egg and helps to thin the lining of your uterus.

Period pain (dysmenorrhoea)

Most women experience period pain at some point in their lives. It’s common for period pain to start when you begin your period and last for 2-3 days. You may suffer from cramps around your stomach or a dull pain around your back and thighs. Period pain usually occurs when your womb contracts to shed the lining – this prevents the usual flow of blood through nearby blood vessels, which can cause you pain. Simple changes to your lifestyle can help ease your period pain. If you keep fit and healthy throughout your menstrual cycle it can really make a difference. Smoking may increase your risk of period pain, so it’s best to avoid during your period or give it up completely. You can try to attempt gentle exercise as it can help to relieve pain and stress. Alternatively, you could consider relaxation techniques such as aromatherapy, massage, acupuncture, meditation and yoga. Heat can help to soothe any discomfort you may have, so try having warm baths or showers or apply hot water bottles and heat pads to painful areas on your body.

When should you see the doctor?

Period problems are a very common reason for women to go to the doctor – one in twenty women will consult a doctor about period related problems in any given year. If you notice anything unusual (for you) in your cycle or you start to notice bleeding in-between periods, make an appointment to see your doctor. Generally, it won’t be anything to worry about but it’s best to be sure.

If your periods are very heavy and painful, have a chat with your doctor, who will advise you on a suitable course of action. In some cases, your doctor may prescribe anti-inflammatories or suggest you try the contraceptive pill.


Ovulation usually occurs around 14 days after the first day of your last period. If you are trying to get pregnant it’s best to have sex at least every two days. Sperm can live for up to seven days, so having regular sex means sperm is more likely to be available when you ovulate. If you do not wish to get pregnant, you should use contraceptive measures.


Feeling a bit rough before your period? You might be suffering from premenstrual syndrome, commonly known as PMS. Learn more about PMS here.


Always read the label.
If you want to report a side effect or quality complaint, please contact your health care professional (e.g. physician or pharmacist), or the Health Products Regulatory Agency (HPRA), or go to the “Contact” menu at
Enquiries can also be directed to

Unfortunately we are still experiencing supply issues on the following Canesten products; Canesten Combi, Canesten 500mg pessary, Canesten 200mg and Canesten Duopak. Canesten Soft Gel Combi will be available in store from late January. Supply of Canesten 2% Thrush cream and Canesten 1% cream is unaffected by the supply issue. This website will be updated as further updates come through. Apologies for the inconvenience this is causing to pharmacies and our customers.