When will I get my period, and what are the best days to get pregnant? By understanding your menstrual cycle, you can answer these questions. Learn about the four phases of the cycle and how to track your period easily.

What is a menstrual cycle?  

Each month, your body prepares for a possible pregnancy. If you don’t get pregnant, the lining of your uterus sheds through your period. A menstrual cycle usually lasts between 21 and 35 days.

The phases of the menstrual cycle  

Your menstrual cycle has four important phases. Each phase does something different in your body:

1. Menstruation: This is when you get your period. Your body sheds the extra lining in your uterus because you're not pregnant. This usually lasts between 3 and 7 days.

2. Follicular phase: While you're still on your period, your body starts getting ready for a new ovulation. Your ovaries start maturing new eggs, and the uterine lining thickens.

3. Ovulation: Around the middle of your cycle, one of your ovaries releases a mature egg. This is called ovulation. If the egg isn’t fertilized, it leaves your body.

4. Luteal phase: After ovulation, your uterus prepares for a possible pregnancy. If there’s no fertilization, the lining breaks down, and your period starts again.

Why is the menstrual cycle important?

Your menstrual cycle is important because it shows that your body is working properly (and when you're fertile). It gets your body ready every month for a possible pregnancy. By knowing your cycle, you’ll understand what’s happening in your body and why you might feel differently at certain times.

How do I know when I’ll get my period?  

The time between the first day of your period and the day before your next period is your menstrual cycle.

Step 1: Write down the day your period starts and ends. These are the first and last days of your cycle.

Step 2: Count the number of days in between. That number is the length of your cycle.

By doing this every month, you’ll get a better idea of how long your cycle is and when to expect your next period.

Why is my period sometimes irregular?  

It’s normal for your period to be a little different every time. Sometimes your cycle might be shorter or longer. This can happen for a few reasons:

- Your body is adjusting: Especially in the first few years after your first period, it can take time for your cycle to become regular.  

- Stress: If you’re worried or stressed, it can affect your cycle and make it irregular.  

- Changes in your body: If you grow quickly or exercise a lot, your cycle can change.  

If your period stays irregular, and you’re worried, it’s a good idea to visit your doctor.

Tips for tracking your menstrual cycle  

Tracking your cycle can be really helpful! It helps you know when your next period will start so you can be prepared. Here are a few easy ways to do that:

1. Use a calendar: Mark the first day of your period each month. Then count the number of days between the first days of your periods. This helps you understand how long your cycle is.

2. Download a period app: There are lots of free apps where you can log your period days. The app will then calculate when your next period is likely to start. Popular apps include Flo, Clue, Clover, or the Health app*

*For iPhone users only.

3. Listen to your body’s signals: Sometimes your body gives you signs that your period is coming, like cramps or tender breasts. These signs can help you know when your period is about to start.

Frequently Asked Questions about the Menstrual Cycle

When am I fertile?  

You’re fertile around the time of ovulation, which is when your ovary releases an egg. For example, if your cycle is 28 days long, ovulation usually happens around day 14. If you have sex between days 10-14, you have the highest chance of getting pregnant.

How much do I bleed during my period?

On average, you lose about 30 to 50 milliliters of blood per day. This might sound like a lot, but it’s roughly the same as two to four tablespoons. Most girls bleed the heaviest during the first two days of their period.

Why do I sometimes get cramps in my lower stomach during my period?

Your uterus contracts to shed its lining. This can feel like cramps in your stomach or lower back. The pain is usually strongest in the first few days of your period. Using a heating pad, resting, or taking a mild pain reliever can help with the discomfort.

What if my cycle is irregular?

It’s normal to have an irregular cycle, especially in the first few years after you start having periods. However, it’s a good idea to see your doctor if your period doesn’t happen for more than 42 days.

Getting your period is something that happens every month. By understanding how your cycle works, you can be ready for it. Whether you want to know when you’re fertile or just want to track when your period will come, knowing your cycle helps.

Remember, every cycle is different, and it’s normal for the length and symptoms to vary, especially in the first few years after your first period.