Fast Facts: What You Always Wanted to Know About Your Menstrual Cycle

Get the information you need to better understand your period

By Michelle Sabia, MPH, CPH
I February 28, 2023

Some people are embarrassed to talk about periods, even though they’re a normal part of female biology. If that includes you, you might have questions about how your period changes and affects your body throughout your life that you don’t know how to ask, or who to ask — especially if you have a male medical provider. We’re here to help with answers to some common questions about your period.

Discharge is normal

Vaginal discharge is the fluid that comes out of your vagina that’s often clear or whitish. Everyone with a vagina has vaginal discharge — it helps keep your vagina clean and lubricated. The color of your discharge and how much of it you have can change throughout your monthly cycle and throughout your life as your hormones change. If your discharge has a strong odor or a different color than normal, it might be a sign of an infection or other condition.

PMS is real

Premenstrual syndrome (PMS) usually begins about seven to 10 days before you get your period. It affects everyone differently, and might include symptoms that are emotional (like mood swings), physical (like bloating) or both. Having PMS is common: 9 out of 10 women report they’ve had it.

PMDD can disrupt your daily life

Premenstrual dysphoric disorder (PMDD) is similar to PMS, but the symptoms — especially sadness, anxiety, moodiness, irritability and anger — are worse, and can affect your daily life more. Between 3% and 9% of people who menstruate get PMDD. If you think you have it, track your symptoms to show your medical provider. You might be able to ease your symptoms by exercising, eating more complex carbs such as whole grains and vegetables, getting more calcium, and practicing stress management methods.

You can get pregnant during your period

Though not very common, if you have unprotected sex during your period, you can still get pregnant. This is more likely to happen if you have irregular periods or a shorter cycle (when you get your period every 24 days or less). If you have sex during your period and are not trying to get pregnant, you should use your preferred method of birth control.

Your period might be different from your friend’s period, but that doesn’t mean it’s irregular

Every person’s period is unique. The average period comes every 21 to 35 days, and bleeding usually lasts between two and seven days.

You might be experiencing an irregular period if:

You miss your period one month
Your period comes earlier or later than usual
Your PMS symptoms are different from what you normally experience
Your blood flow is heavier or lighter than your regular period
You bleed for longer than you usually do
You get your period at a different time each month

Options for delaying or stopping your period

Your period can sometimes come at an inconvenient time, especially if you’re training or deployed. You might also benefit from stopping your period if you have a condition that is made worse by monthly bleeding, like anemia or endometriosis. Certain types of hormonal birth control can delay or stop your period.

Don’t ignore heavy bleeding during your period

The amount of blood you typically lose during a period is about two to three tablespoons. There are a lot of reasons why you might bleed more than that, such as uterine fibroids, intrauterine devices (IUDs) or a hormonal imbalance. You should talk to your medical provider if you have any of the following symptoms:

Blood that soaks through one or more pads or tampons every hour for several hours in a row
The need to use double protection to control your bleeding
The need to change period products during the night
Periods that last longer than seven days
Blood clots as large as or larger than a quarter
Heavy bleeding that interferes with your regular lifestyle
Constant pain in your lower abdomen during periods
Tiredness, fatigue or shortness of breath

Perimenopause can start earlier than you think

People with a uterus usually go through menopause in their late 40s to early 50s, but perimenopause — the time leading up to menopause — can start as early as your mid-30s. During perimenopause, your period may come sooner or later than you’re used to, and you may even skip some periods. Your flow can change as well, becoming lighter or heavier. Eventually, your periods will stop completely. After 12 months in a row without having a period, perimenopause ends and you reach menopause.

Symptoms of perimenopause vary and can include: