Discover Why Your Period Comes Early

Although an early menstruation doesn't usually imply great danger, it's best to consult a gynecologist. Hormonal changes, weight variations, and stress are the most frequent causes. Read more about why your period comes early.
Discover Why Your Period Comes Early
Leonardo Biolatto

Written and verified by the doctor Leonardo Biolatto.

Last update: 18 July, 2022

The menstrual period is one of the processes that most conditions women’s lives throughout their fertile years. It’s a complex process and there are many factors that influence it. Therefore, it’s common for there to be alterations on many occasions. So, at some point, your period may have arrived before you expected it. With that in mind, today, we want to talk about why your period comes early.

The menstrual period usually appears every 28 days especially in adult women who’ve gone through puberty and are no longer prone to hormonal changes. However, this isn’t always the case. In fact, every woman has a different cycle pattern and bleeding with specific characteristics.

Although the range of normality is established between 21 and 35 days between periods, there are exceptions in which the period may appear earlier or later. So, keep reading and discover why your period may come early and what to do if it happens to you.

Why your period comes early

As we mentioned above, periods usually come every 28 days. However, this depends on each woman’s cycle and her stage in life. For example, we must keep in mind that during the first years of menstruation, the cycle is very variable.

The same happens just before the onset of menopause. In both stages, it’s common to find women who have early periods that may come to repeat themselves in the same month. The opposite also happens, where a woman’s period comes later than usual.

The action of different hormones, such as estrogens and progesterone, produces the menstrual cycle. These substances are synthesized by a complex mechanism involving brain structures and the ovaries.

What happens is that many different stimuli control hormone production. In addition, when there’s an injury to any of the organs involved, alterations can occur, resulting in irregular or premature menstruation.

A woman holding a clock in front of her bare abdomen.
Changes in menstrual periods are due to multiple causes, which are mainly hormonal.

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What other factors are there?

One of the main factors that influences menstruation is stress. When a woman has high levels of anxiety, it’s common for her period to be one of the first things that’s affected. In many cases, her period comes early, but it may also come late or become atypical in how it appears.

Another important factor in this situation is nutrition. In order for a woman to menstruate, she needs to have a minimum amount of body fat. Eating habits have a significant influence on a woman’s period, so starting a diet or changing it can cause the period to come earlier.

Interestingly, body mass index can influence menstruation. Very thin women, as well as those who are overweight, may find irregularity of the menstrual cycle in common.

You should also keep in mind that certain medications and contraceptives cause your periods to be more spaced out or closer together. A special example is the morning-after pill. This pill causes a hormonal imbalance in order to prevent pregnancy, which can sometimes involve an irregular period.

A woman holding a blister pack of birth control pills.
Birth control pills are great regulators of the menstrual cycle, but, in certain women, an adverse effect is a sudden change in the timing of their periods.

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What should I do if my period comes early?

The truth is that your period coming early shouldn’t cause you to worry excessively. As we’ve already mentioned, many factors influence the menstrual cycle, and most often, it’s nothing pathological.

However, if this happens frequently or you’re concerned about another aspect of your cycle, it’s best to see a gynecologist. It’s also important that you review your diet and your exercise habits, as intense physical activity alters your period.

It’s best for your doctor to perform a proper examination and any tests they deem necessary. Just in case, it’s important to rule out any diseases or major hormonal imbalances that could be behind the early arrival of your period.

Periodic doctor’s visits are also important when it comes to controlling your period

If you have any questions or discomfort, consult your doctor. Seeing your gynecologist regularly will allow you to detect any problems that could arise and will also put your mind at ease.

When the health professional consults you about your menstrual rhythms, they’re making sure that you maintain a regularity that’s considered normal. Write down your days on a calendar so that the information you provide at the office is as accurate as possible.


All cited sources were thoroughly reviewed by our team to ensure their quality, reliability, currency, and validity. The bibliography of this article was considered reliable and of academic or scientific accuracy.


  • Ciclo menstrual | womenshealth.gov. (n.d.). Retrieved May 5, 2020, from https://espanol.womenshealth.gov/menstrual-cycle
    Ciclo menstrual y fertilidad | Embarazo y maternidad. (n.d.). Retrieved May 5, 2020, from
  • Thakur, Harshada, et al. “Association of Body Composition, Nutritional Status and Menstruation among Early Adolescent Girls.” Indian Journal of Public Health Research & Development 9.5 (2018): 509-514.
  • Bae, Jinju, Susan Park, and Jin-Won Kwon. “Factors associated with menstrual cycle irregularity and menopause.” BMC women’s health 18.1 (2018): 36.

This text is provided for informational purposes only and does not replace consultation with a professional. If in doubt, consult your specialist.