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Your First Period Guide: Age, Symptoms, Duration & More

Your First Period Guide: Age, Symptoms, Duration & MoreYour First Period Guide: Age, Symptoms, Duration & More

By: Dr. Melisa Holmes, OBGYN, & Founder, Girlology

If you’re looking to learn more about when to expect a first period or how to manage it, congratulations on being prepared! Knowing what to expect when getting your period and having accurate information can really increase confidence and decrease worries as puberty progresses and first periods arrive! So whether you’re preparing for your first period or you’ve already started and just want to learn more about it, we’ve got you covered.

What Exactly IS a Period?

There’s a lot to understand about the menstrual cycle and periods, but basically, a period is something that begins to happen a couple of years after puberty begins. When you have a period, it means you have bloody fluid that is released from the uterus and trickles out of the vagina. Most periods last 3-7 days, then about every month, it happens all over again. It’s called the menstrual cycle because it is a cycle that repeats itself over and over. It may sound weird, but it’s totally normal, it happens to half of the world’s population, and it’s actually a sign of good health.

Why Do Girls Get Periods?

The whole reason people go through puberty is to be able to reproduce in the future (to continue the human species!). If you have a uterus and vagina, you have the potential to grow a baby. A period is a sign that your uterus (the place inside the female body where babies grow) is beginning to prepare for the possibility of pregnancy. It does that by forming a thick, lush lining where a baby could grow. If there’s no pregnancy, the uterus releases the lining as a period, then it starts over creating a new, fresh lining over the next 3-5 weeks. If there’s no pregnancy, there’s another period, and it starts over. Periods happen this way from puberty until menopause which is when the menstrual cycle stops around age 50. Check out this guide to learn more about periods and the menstrual cycle.

When Will I Get My First Period?

As a doctor, one of the most common questions I hear from young girls is, “When will I get my first period?” Although there’s no crystal ball to tell you exactly when you’ll start, there are definitely some hints. 

How old will I be?

It’s normal to get your first period as young as age 9 or as old as age 16, but the average age that most people start their periods is around age 12. Your age has a lot less to do with your first period than the way your body is changing during puberty.

What are the Signs My First Period is Coming Soon?

The best way to predict your first period is to notice the changes happening to your body during puberty. The body changes that predict your first period most accurately are your breasts, pubic hair, and height. Most periods start 1½ to 3 years after breasts first start growing, when the pubic hair has filled in, and about 6 months after your fastest growth in height. Obviously, that doesn’t tell you the day, the week, or even the month it will start, so you will just have to accept that your first period will be a bit of a surprise. That’s why it’s so helpful to be prepared – just in case!

What Should I Expect?

You already know that a period is when the lining of the uterus is released and flows out of the vagina as bloody fluid. Great, but what exactly will that feel like? Does it come out fast or slow? How much fluid will there be? How long does it take? Will it hurt? What does it look like? It’s normal to have all these questions, so keep reading to be a period pro!

What will it look like?

If a period is made of bloody fluid, you would expect it to look like blood, right? Well, sometimes period flow can look thinner or thicker than “normal” blood. First periods sometimes show up as a thick dark “smear” in your underwear. Dark? Yep, the color can definitely be different than you expect, ranging from deep red, to maroon, brown or even black. That happens because blood changes color over time. Sometimes your period blood has been waiting in your uterus or vagina for a while before it comes out, so it isn’t the color of “fresh” blood like you’d see if you cut your skin (the older the blood is, the darker it looks). The color doesn’t mean anything about your health, so just know that if you see brown stuff in your underwear (and you’re sure it’s not poop), it’s probably your period.

How much blood?

First of all, your period will trickle slowly out of your vagina over several days. It’s not a stream like when you pee, and it doesn’t come out all at once. Although everyone’s period is a little different, most of us release about a half cup to a cup of fluids over the entire period. It’s normal for the first day or two of your period to flow heavier than the last couple of days because the flow typically gets lighter toward the end of your period. Those differences in flow mean that it’s normal to use 2 or 3 different sizes of period protection products (for example: pads, tampons, and cups) during each period because of these normal changes in flow.

How long will it last?

On average, periods last anywhere from 3 to 7 days. After you’ve had several periods, you’ll learn what’s normal for you. If you’re not sure if your normal is really normal, you can check out this guide on how to Know Your Flow and it’s never a bad idea to talk to your gynecologist.

Will it hurt?

Since periods involve blood, it seems only natural to think that they might hurt. The good news is that first periods usually don’t hurt! In fact, you might even start your first period and not even know it until you see it! You may get menstrual cramps, which involve a mild crampy feeling in the lower abdomen. Cramps happen because the uterus is made of muscle, and muscles can cramp when they’re working hard. There are lots of ways to ease cramps so your period doesn’t slow you down!

Should I use pads or tampons?

Obviously, if you have bloody fluid flowing from your vagina, you’ll want to do something to keep it from soaking through your clothes. That’s what pads and tampons are for! A period pad is an absorbent, fabric-like pad that sticks to the crotch of your underwear and catches your period flow as it comes out. A tampon is period protection that fits inside your vagina to absorb the flow before it comes out.

There are lots of different sizes of pads and tampons. Large sizes are good for heavier period flow. Smaller sizes are best for lighter flow.

A lot of people think you have to use pads with your first period, but there’s no reason why you can’t use a tampon if you want. It’s your choice! Both pads and tampons are safe, even for your first period. The most important thing is to know how to use them properly and safely. You can learn how to insert a tampon here!

When will I have another one?

After your first period, your second one can be pretty unpredictable, too. Most expect it one month after the first period, but in reality, it's pretty normal for it to happen anywhere from 3 weeks to 3 months after your first period.

Once you’ve had a few periods, the best way to predict future ones, is to write down the dates of every period you have and count how many days there are from the start of one period to the start of the next. That tells you your cycle length. Obviously you’ll need to have a few periods before you can do this, but it is super helpful for staying aware and prepared!

When you keep track of your periods like that, it’s called “period tracking” (so creative!). There are lots of ways to track your periods. You can write them on a calendar, in a journal or notebook, or use a period tracker. Make sure you record the day you start and every day you have your flow. You might also want to note when your flow is heavy and when it is light. This is the best way to know your flow so you can be aware and prepared!

Are There Other Period Symptoms?

Besides tracking the timing of your cycle, you may also know a period is near when you develop certain symptoms that are caused by the menstrual cycle hormones. The most common symptoms reported before a period include bloating, moodiness, food cravings, breast tenderness, headache or menstrual cramps. Within a day or two after the period begins, the symptoms disappear naturally. If you experience some or all of these symptoms before most of your periods, it’s called Premenstrual Syndrome or PMS.

Your First Period Guide: Age, Symptoms, Duration & More
Are you expecting to get your first period? Or are you new to your menstrual cycle and have questions? We've got answers and resources to help prepare you.