6 possible reasons why your period could be irregular.

Image: iStock.

The only thing more annoying than getting your period unexpectedly (usually on the day you wore your nice new undies/white pants)? Not having the slightest clue when it’s going to come.

While a period that’s a few days out is manageable, if it’s happening regularly it could be in response to something you’re going on in your body – or a sign of a bigger issue.

1. You’re pregnant.

Pregnancy is one of the most common causes of irregular periods, so it always needs to be excluded,” says Sapphire Medical Practice‘s Dr Dasha Fielder.

The easiest way to rule this out is to do an at-home pregnancy test or to visit your doctor. In the mean time, note if your body is showing any other common symptoms such as tender breasts, the frequent need to go to the bathroom, nausea and fatigue.

2. Your contraception.

The contraception you use could offer an explanation as to why your period is being irregular.

“Birth control works to prevent ovulation by supplying the same dose of female hormones every day, and turns off natural production of sex hormones which avoids the surge in oestrogen and follicle stimulating hormone (FSH) required for ovulation,” explains Dr Fielder.

This is why people on the Pill can experience lighter, less frequent or even non existent periods. (Post continues after gallery.)

3. Extreme diet or exercising.

Making big changes to your diet or workout regime can often affect the frequency of your period.

Extreme exercise and diet can change your cycle by affecting your hormones and making your body think that you are in a life threatening situation with extreme weight loss,” explains Dr Fielder.


As a result, your body responds by shutting down unnecessary function and prevents you from reproducing.

4. Stress.

We already know the many ways stress can affect your health, but it could also be a factor behind your period being out of whack.

In much the same way as extreme dieting or exercise, stress can affect your hormones and menstruation by sending your body into its ‘fight or flight’ response, sending a signal to your brain to stop ovulating.

Stress can impact your period. (Image via iStock.)

5. A sign of something bigger.

In some cases, an irregular or absent period could be the sign of a more serious condition, such as Polycystic Ovary Syndrome (PCOS), a medical condition that causes tiny cysts to form on ovaries.

"PCOS is a complex condition that results in infrequent menstruation and other signs such as excess in male hormone that can cause changes in your voice, skin with acne and excessive hair growth," says Dr Fielder.

Health conditions like sexually transmitted diseases, thyroid disorders, endometriosis and diabetes can also cause irregular periods, so it's best advised to see your doctor to diagnose or rule these out.

6. Age.

According to Dr Fielder, it's not uncommon for your cycle to change simply because you're getting older.

"In adolescent years when menstruation first commences it is very common for it to be irregular - something that happens again at the other end of the spectrum in the perimenopausal years," she says.

It's around the age of 48 and older that you could see your periods change in frequency and duration as you approach menopause.

If you're concerned about your menstrual cycle, it's always best to consult your doctor to pinpoint what's going on.

How do you deal with irregular periods?