Irregular periods

An irregular period happens when your period starts at an unexpected time during your menstrual cycle.¹

Usually, menstrual cycles last 28 days, and your period marks the start of a new cycle. However, it is normal for menstrual cycles to last anywhere between 28 and 35 days.²

The average period lasts anywhere from 2 to 7 days.²

If your menstrual cycle and period are different from these average ranges, then you may have irregular periods.¹

It may seem concerning, but it’s important to remember that many factors can change the length of your cycle.

Early pregnancy, menopause (in women aged 45 and 55), and stress, are some potential causes for your irregular periods.^{1, 3}

If you’re going through puberty, you may notice some irregularity – especially in the first two years of your periods.^{1, 3}

Weight loss or gain, contraception, and medical conditions may also cause your periods to become irregular.^{1, 3}

Some of the conditions that may affect your periods include:

Your GP can provide advice and refer you to a specialist called a gynaecologist if you need further information and support.

There are many ways to track your period and menstrual cycle length.

Some of these methods include:

Though they can be effective when trying to understand when your cycles may start, they cannot replace contraception.

If you decide to track your cycle on a calendar or in a diary, it’s important to remember that the first day of your cycle is the day when your period begins. The last day is when your next period starts.⁴

If you need advice about the contraceptive options that are right for you, talk to your local pharmacist or GP.

Even though you have irregular periods, you may still be able to get pregnant. However, it may be more difficult as you may not be ovulating (producing a mature egg) every month.¹

If you want to try for a baby having sex every 2 to 3 days may help increase your chances of becoming pregnant.¹

Talk to your GP if you’ve been trying for a year or more. They may want to refer you to a gynaecologist. They may also want to discuss options like fertility treatments with you.

There are many reasons for irregular periods. Depending on the cause you may be recommended different types of treatment.

Talking to your pharmacist or GP will help in narrowing down the options that are right for you and your symptoms.