i'm guessing you're feeling a bit nervous about telling your mum, huh? that's totally normal, by the way. i remember when i first got my period, i was so scared to tell my mum too. i thought she'd be all weird about it or something. but honestly, she was really cool about it.
i swear so many girls think they're the only one who's ever felt this way, but trust me, you're not alone. it's a big deal to start your period, and it can be kinda overwhelming. that's why it's okay that you haven't told your mum yet - you're just taking some time to process everything, and that's totally fine.
okay, so your period is a natural part of life, and it's not something to be ashamed of. it's just your body's way of getting ready for the possibility of having a baby one day. but for now, you just need to focus on taking care of yourself and getting used to this new thing your body is doing.
why don't you try writing your mum a note or something, and then you can talk to her about it together? that way, you can break the news to her in a way that feels comfortable for you. and remember, your mum loves you no matter what, and she'll be there to support you through all of this. you've got this, and your mum will help you figure everything out.