Early menopause: I'm 15 and already know I won't have kids
Two years ago, Annabelle's periods stopped. Since then she's been told she has early menopause and found out she won't be able to have children.
Only one in 10,000 women under the age of 20 are diagnosed with early menopause.
Despite being one of the unfortunate few, Annabelle says she knows "there are people going through worse". She's told her story as part of the BBC's Young Reporter project.
You can find advice if you or anyone you know has concerns about missing periods at BBC Advice.
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