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3 signs your daughter is about to start her period

Inside: What are the first signs your daughter is about to start her period? Find out what signs to look out for, so that you can prepare your daughter for her first period (before it already happens). 

If I could invent a machine that could predict a girl’s first period to the exact day (even to the week), I would be a rich person. As it is the one thing that tween girls want to know!

I have a Youtube Channel for Sex Ed Rescue, and for some strange reason, a lot of tweens have been watching my puberty content. So many that I’ve had to start a channel with age-appropriate information just for them – Puberty Talk. And they keep on asking me when they’ll get their first period. It is something that they really want to know, and the other tweens will make comments about how long a wait it is, for this life-changing event to finally happen.

But back to that period-predicting machine, it is impossible to accurately predict when a first period will happen. Predicting the first period isn’t easy, as it is different for every girl.

But there are three things that first have to happen to a girl before periods will start.

You’ll find more information about puberty (and periods) in my Puberty 101 page. And if you’re feeling unsure about how to talk to your child about periods, you’ll find some tips in this blog post about the “period talk”.

Signs your daughter is about to start her period

It may help your daughter to know that every girl is different. Some girls will start their period earlier than other girls. And some girls will start their periods later. Some girls may be as young as nine or 10. Whereas some girls maybe 14 or 15. The average age for a first period is 12 or 13.

So as you can see there is a wide range of ages, with the first period usually happening anywhere between the ages of 9 to 15 years of age.

Sometimes we can predict that a girls first period will happen around about the same age that it did for her mother (plus or minus a year). So if had your first period at the age of 11, you could then expect your daughter to be starting her period earlier than the other girls, just like you. But this isn’t 100% accurate, as I hear from many parents who’s daughters started their periods much earlier or later than they did. Plus research tells us that the average age of puberty in girls today is much earlier than it was for previous generations. There are many theories as to why puberty is occurring at earlier ages, attributing it to a wide variety of genetic, hormonal, nutritional and environmental factors. You can learn more in this article about the stages of puberty in girls.

There are three changes that have to happen before your daughter has her first period. Once these three changes have started, you will finally have the first signs your daughter is about to start her period. Just remember though, that every girl is different and her period will start when her body is ready for it. And the changes don’t necessarily have to happen in this order.

1. Breasts

Your daughter will have been developing breasts for about two years. Now, this doesn’t mean that her breasts will be fully developed and adult-like. It just means that she will have had something growing on her chest for about 2 years. So she may still be relatively flat-chested or she may need to be wearing a bra. Remember, every girl is different!

girl trying on mums bra
Some kids can’t wait for their first bra!

2. Pubic or underarm hair

Your daughter will have had some pubic and/or underarm hair for at least the last four to six months. Now, again, this doesn’t mean that she will have a full crop of adult-like hair. It just means that she will have started to grow hair of some sort, in the pubic area or under her arms.

3. Vaginal discharge

Your daughter will have been having some vaginal discharge for the last three months. Some girls can have this up to two to three years before their first period. In this case, if it starts to get heavier and more frequent, then that is a sign that her period is on its way, sometime in the next 3 to 6 to 12 months! You can’t get much more accurate than that!

Vaginal discharge can be a little tricky to explain to girls. She may notice a white or yellow stain on her underwear or start commenting about feeling wet around her vulval area. Some girls worry when this first happens. They think that they may have wet themselves, or that there is something wrong with them. It is important for your daughter to know that she is normal and that her vaginal discharge will change during her menstrual cycle. Sometimes it will be lighter or heavier and she needs to get used to finding patches of white or yellow on her underwear!

Other signs

Your daughter may also get premenstrual symptoms beforehand, like tummy cramps, backache, headaches, feeling bloated, slight nausea, tiredness and possibly even feel irritable, sad, and/or tense.

Talking means your child is prepared (and not scared).

QUIZ: When will I start my first period?

I’ve created a Quiz to help to look for signs your daughter is about to start her period. Ideally, you can complete this together with your daughter, as it provides a wonderful opportunity to start talking with her about periods. You can find  the ‘When will I start my first period?’ Quiz here, with extra info and videos to explain the answers.

My 13-year-old daughter spotted this quiz on my computer screen and has had a lot of fun testing it for me.

She thinks it is important for girls to know that these three things have to happen before your first period. As she says, now that she has all 3 signs, she now knows that she needs to carry her DIY period kit in her schoolbag, just in case her period starts whilst at school. And for the first time ever, she now takes it to school, instead of leaving it lying on her bedroom floor.

So do go and read my blog post on how to make up your own DIY period kit. You can use anything to hold all the gear your daughter needs for her periods, but this is what I  think makes the best period bag for tween girls. My daughter uses these bags and she really likes them as they are purpose-built to be used when out and about.

Resources to help with talking about puberty

My mission is to create resources that will help you to naturally talk to your kids about sex, all while respecting your personal values.

Which means that inside this website, you’ll find lots of resources to help you with talking to your child about puberty.

My Puberty 101 page includes all of the information on puberty. You’ll find lots of different blog posts to help with talking to your child about growing up.

You’ll find videos about puberty in my Sex Education Videos resource page that you can watch with your child or to learn more about puberty yourself.

You’ll also find an extensive range of children’s books on puberty, for kids of all ages. 

If you get stuck and feel that you need some extra support with talking to your child about puberty, then my book, The Parents’ Guide to Puberty, may be helpful. It’s a straightforward common sense guide that will help you to start having honest conversations that will guide your child through puberty, and strengthen your relationship without feeling embarrassed, awkward or nervous.

Or maybe you’re looking for a video course to sit down and watch together with your child. My friend Rowena from Amazing Me has created a fantastic 2 part interactive course for parents/carers to attend together with their 9 to 12 year old. It’s fun, educational and age-appropriate! You can learn more about her puberty course here.

If you have a child who is expecting their first period, then you may want to consider period pants. Period pants are fantastic for kids who are worried that they won’t know that their period has started until it stains through their clothing for the world to see. My favourite brand for tweens and teens is ModiBodi, as they are good quality and quite absorbent.


If you need some help with explaining sexual intercourse to your child, then How to Talk to Kids About Sex will help you explain sex to your child in a way they will understand. It breaks sex down into simple steps that take the stress out of explaining!

If you’re unsure about how to answer your child’s questions about sex, then I have the perfect book for you! The Sex Education Answer Book will give you age-specific answers to the most common questions kid’s ask parents about sex. Which means you don’t need to worry about finding a child-friendly explanation that your child understands. 

And if you get stuck, feel free to get in touch! You can contact me here.


  • A Blessing Not a Curse: A Mother-Daughter Guide to the Transition from Child to Woman by Jane Bennett. 2002. Sally Milner Publishing Pty Ltd.  Bowral.
  • Adolescence and Puberty. Edited by John Bancroft and June Machover Reinisch. 1990. Oxford University Press. New York.
  • Gender Differences at Puberty. Edited by Chris Haywood. 2003. Cambridge University Press. Cambridge.
  • Handbook of Child and Adolescent Sexuality: Developmental and Forensic Psychology. Edited by Daniel S. Bromberg and William T. O’Donohue. 2013. Elsevier. Academic Press. Oxford.
  • Puberty: Physiology and Abnormalities by Philip Kumanov and Ashok Agarwal. 2016. Springer International Publishing. Switzerland.

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