You have an irregular period if the length of your menstrual cycle (the difference between the start of your period) keeps changing. Your period may come sooner or later. The average menstrual cycle lasts 28 days. After puberty, many women develop regular cycles with similar lengths between periods. But it's not uncommon for it to vary by a few days each time.
There are many possible causes of irregular periods. Sometimes they are just normal for you and there is no specific reason for irregular periods.
Here are some of the common causes:
- Puberty - your period may be irregular for the first year or two
- The start of menopause (usually between the ages of 45 and 55)
- Early pregnancy - take a pregnancy test to rule this out
- Some forms of hormonal contraception - such as the birth control pill or the intrauterine system (IUS)
- Extreme weight loss or gain, excessive exercise or stress
- Medical conditions - such as polycystic ovary syndrome (PCOS) or a problem with your thyroid gland.
When should you see a doctor?
- Your period suddenly becomes irregular and you are under 45
- Your period is less than every 21 days or more than every 35 days
- Your period lasts longer than 7 days
- There is a big difference (at least 20 days) between your shortest and longest menstrual cycle
- You have irregular periods and you have trouble getting pregnant
It may be nothing, but it's a good idea to get checked out to see what could be the cause.
You may be referred to a gynecologist if more testing or treatment is needed.
You do not need to seek medical advice if you have always had mild irregular periods or if you are still going through puberty.
Can I get pregnant with irregular periods?
It can be more difficult to get pregnant if you have irregular periods because you may not ovulate (release an egg) regularly.
It may help to have sex every 2 or 3 days during your cycle. You don't have to schedule sex around ovulation.