First of all, don't panic!
The first step is to get a pregnancy test.
If you are pregnant, you have several choices.
Support and help is available no matter what you decide to do and no health service staff will tell you off or judge you.
What if I think I'm pregnant?
Your should speak to your school nurse, your doctor or go along to your nearest sexual health service or Youth Health Drop In.
There can be several reasons for this.
When we're young, stressed out, ill, exercising lots or not eating properly, periods can become irregular or stop.
However, if you've had sex since your last period happened, you should have a pregnancy test.
You can buy pregnancy test kits from supermarkets and pharmacies or get them for free from your school nurse, your doctor or your nearest sexual health service or Youth Health Drop In.
What if the result is positive?
Get support from your school nurse, GP, trusted friends, relatives or teachers if you can.
You have a lot to think about and talking things through will make it easier to work out what to do next.
If you tested yourself, it's important that you see your doctor or school nurse straight away. They will talk to you about what your options are what to do next.
If you're not ready to tell anyone you know, you can call Childline free at any time on 0800 1111.