Delayed start to periods (primary amenorrhoea)

Some people start their periods later than others, and that’s normal. If your mum or sister started their periods later, you may too. It's good to chat with them about this if you can.

A delay in starting periods isn't usually anything to worry about. If you haven’t started your period by around 16, it’s a good idea to see your doctor to find out why it hasn’t happened yet.

Reasons for delayed periods can include:

Whether you need treatment will depend on the reason why your period is delayed. When you speak to your doctor, they'll be able to talk you through any treatment options, if needed.

It's ok to ask any questions about your care to help you get the information you might need.

Irregular periods

Some people may experience irregular periods that don’t come every month. This is often the case when girls start their periods but it can also be caused by things like stress, certain health conditions or pregnancy. Irregular periods can also be a sign of menopause.

If you think you might be pregnant, take a pregnancy test as soon as possible.

Further information about irregular periods

Bleeding between periods (spotting) or bleeding after sex

Some people will bleed between periods (known as ‘spotting’) or bleed after sex. There are lots of different reasons why this might happen. If you experience this you should speak to your doctor.

Periods and pregnancy

If you're trying to get pregnant, or you don't want to get pregnant, it's important to know how your period is linked to fertility.

Further information about periods and pregnancy

Non-urgent advice: Speak to your doctor if:

  • you’ve started your period but haven’t had one for a while (3 to 6 months)
  • you bleed between your period, after sex or after the menopause

Last updated:
11 May 2022