Menstruation, or a “period,” is a normal part of growing up for girls. Even though it’s common, it’s not always talked about. That can lead to confusion or worry. This guide will help you understand what to expect and when to talk to a doctor.
When Does Menstruation Start?
- Most girls start their period around age 12
- It can happen as early as age 9 or as late as age 15
- Talking to your mom or female relatives can help you know what might be normal for your family
What Are the Signs It’s Coming?
Before your first period, your body will go through puberty. Signs include:
- Breast development
- Pubic or underarm hair
- Growth spurts (getting taller quickly)
Once these changes begin, a period may start in the next 2 to 3 years. The first period is often light—just a few spots of blood.
What Is a Normal Period?
At first, periods may not be regular. That’s totally normal! Over time, they usually become more regular:
- Cycle length: Around 28 days from the start of one period to the next (can range from 21–45 days)
- How long it lasts: 3 to 8 days
- Flow: Can be light or heavy—everyone is different
Periods may change over time, especially during the teen years.
When to Talk to a Doctor
It’s important to talk to your doctor if:
- You haven’t started your period by age 15
- Your periods happen less than every 45 days
- Your period lasts longer than 8 days
- You have severe cramps, very heavy bleeding, or feel sick during your period
Remember: Your period is a vital sign—just like your heart rate or blood pressure. It’s an important part of your overall health.
Common Misconceptions
- “You can’t exercise during your period” – Not true! Moving your body can actually make you feel better.
- “PMS is just an excuse” – Also not true. PMS (premenstrual syndrome) is real and can cause mood swings, cramps, or tiredness. Talk to your doctor if it’s affecting your daily life.
How to Take Care of Yourself
During your period, it’s helpful to:
- Get extra sleep
- Eat healthy foods
- Stay hydrated
- Move your body if you feel up to it
Period Product Options
There are many ways to manage your period. You can choose what feels right for you:
- Pads – Stick to underwear, easy to use
- Tampons – Go inside the body, good for swimming
- Period underwear – Reusable and absorbent
- Menstrual cups or discs – Reusable products that go inside the body
Ask a parent, doctor, or trusted adult if you’re unsure which to try first.
Every woman’s body is different, and that’s okay! If you have questions or concerns, Valley Health is here to help.