Ugh, menstrual cycles. Women, you know the drill. Besides the typical activities like having to change your tampon every few hours, you’re also fatigued. And you’re snappy. The cramps feel like you’re getting stabbed in the ovaries. You want chocolate. You’re crying over a Folgers commercial. (Just me? I digress.)

Point is, having your period isn’t really that fun for anyone involved. That’s why we all typically count down the days until Aunt Flo leaves for the month. Which is usually…well, how long exactly?

According to the Mayo Clinic, an average menstrual cycle can last anywhere from two to seven days. That’s a pretty big range! That’s because the truth is, the length of your period varies. Some women are lucky enough to average a pretty short period, but others have it much longer.

Everyone’s bodies and hormones are different, so it only makes sense that the length of your period can vary. There are a number of factors that can play a role in this. Here are 5:

1. Your weight

   Putting on a few extra pounds can cause the body to produce extra testosterone, which can prevent ovulation, and can cause a short period, or even no period at all. That said, being underweight (or dropping weight fast) can also have an impact on the length of your cycle—low weight causes low estrogen levels, which is imperative for ovulation.

2. Diet and exercise

   We basically just told you that you need to maintain a healthy weight to sustain a normal period length, so it makes sense that what you eat and how often you exercise can also affect the length. Increasing your exercise regimen to the extreme or getting caught up in severe dieting can cause you to drop an unhealthy amount of body fat. That makes it difficult for your body to balance hormones and can cause a super light and short period, or even cause your period to stop altogether.

3. Smoking or alcohol use

   Excessive cigarette smoking may cause changes to levels of estrogen, progesterone, and other hormones associated with your period, according to a study published in BMJ. Additionally, drinking too much alcohol on a daily basis can cause an imbalance in your hormone levels, which can affect your cycle.

4. How old you are

   As you get older, your period has a tendency to change in length, especially for older women who may be nearing menopause. This is also true for young teens just starting their period—the length will likely be irregular and may take up to a year to stay at a consistent length.

5. Whether you have a medical condition

   Certain hormonal disorders such as polycystic ovary syndrome (PCOS) or thyroid disease such as hypothyroidism or hyperthyroidism, and others can also cause infrequent or prolonged menstrual periods. If you’re showing signs and symptoms of a condition such as these, make an appointment with your doctor to get evaluated and hear your options.

How long is your average period? Do you notice the length can change with some of these factors?