Why Did My Period Come Early this Month? Possible Causes

Why are Girls Getting Their Period Earlier?

Key takeaways

  1. Puberty is the beginning of the fertility phase of a female and lasts till the age of 50 years. It usually starts at 10-11 years old and comes with physical, psychological, and hormonal changes.  The menstruation cycle marks the start of the fertility phase and completes its cycle every month, consisting of 20-21 days. 
  2. The menstruation cycle normally consists of 20 days, which means the gap between your two periods, and when the cycle ends, you will get your period. There should be a 20-21-day gap between your two periods, which will normally last for 4-7 days. 
  3. If you get your period a week earlier than expected, but there is a gap of 20-21 days, it is totally normal and nothing to worry about. If your menstrual cycle is less than 20 days, causes could be Implantation bleeding, PCOS, Endometriosis, Hormonal birth control, or stress. It’s good to consult your healthcare provider at the right time for correct diagnosis and prescription. 


Getting your periods (Menses) a week early is usually normal, as there should be 20-21 days of a minimum gap between your last and present period, says
Dr. Richard Honaker M.D.

It’s troubling only if there are less than 21 days and your periods come early before completing its cycle of 20-21 days. Menstruation starts with the start of puberty, which technically is the beginning of the fertility period in every female.

Puberty is described as the beginning of fertility and includes the development of breast buds, pubic hair, a growth spurt, first ovulation, and menstruation.
Let’s discuss all the causes of abnormal menstrual cycle ending in abnormal periods.

What is puberty?

Puberty is described as the beginning of fertility and includes the development of breast buds, pubic hair, a growth spurt, first ovulation, and menstruation called periods. Puberty not only includes physical development but also psychological changes as well. It generally starts from the age of 8-13 and stays till age 50 in females, after which menopause occurs, followed by the post-menopausal period.

In the United States, approximately 50 percent of females will have attained the stage of physical and breast development before age 10. While some parents may mistake extra fat for developing breasts.

Period, a week early. Is it normal?

Having a period a week earlier than expected is normal, and it entirely depends on the overall menstruation cycle, says Dr. Richard Honaker, M.D. The menstruation cycle consists of 20-21 days in total, and you don’t see any vaginal bleeding through that cycle. You only get your period when the cycle completes and the lining is the uterus starts to shed in the form of blood that you observe.

Get all your questions answered right away with our virtual consultation and get a prescription.

It’s troubling only if there are less than 21 days and your periods come early before completing its cycle of 20-21 days. It can be an indication of a lot of underlying reasons except one, which is “Am I pregnant?”. No, you certainly are not. because if you are getting your period regardless of the time, it indicates that there is no fertilization or implantation in the uterus that develops into an embryo first or a baby afterward.

Let’s discuss all the underlying reasons for getting periods early one by one.

What are the early period causes?


Puberty causes a lot of changes in the growth and development of a female, not only physical or psychological but also hormonal. Those hormones that are released and responsible for the pubertal growth of a female are called Reproductive hormones. The rate and amount they get released change with time and can affect your normal menstrual cycle.


Sexually transmitted diseases, e.g, Pelvic Inflammatory Disease (PID), including gonorrhea and chlamydia, can affect abnormal vaginal bleeding, resembling periods, and you will observe abnormal bleeding for a day or two. It can also cause changes in your menstrual cycle.

It’s good to get yourself checked by your healthcare provider if you see similar symptoms.

Experiencing early spotting before your expected period? Consult doctors online now.

Implantation bleeding

Implantation bleeding does not cause your period early but can resemble period bleeding. It happens because of the fertilized egg’s implantation in the uterus’s wall. Some veins in the walls of the uterus get ruptured when implantation occurs, and some of the blood leakage occurs in the form of blood spotting resembling your period.

Pregnancy loss

Pregnancy loss changes the menstrual cycle and might give a period ring earlier than the normal date. Pregnancy loss happens when the fertilized egg detaches itself from the uterus wall, after which the uterus wall detaches itself from the uterus, causing periods.
In case you observe periods when you are pregnant, it indicates that pregnancy is lost and there is no more developing fetus anymore. Getting medical attention as soon as possible is important in case of pregnancy loss.

Did you get your period while pregnant? Get an online consultation now from our doctors online.


PCOS is polycystic ovary syndrome, a disease where water or fluid-filled bags and fluids occupy the space in the uterus attached to the wall of the uterus. It usually happens due to genetic or diet issues in the female and needs medical attention as they might make a female infertile if left untreated.
They will hinder the menstruation cycle in a way that you will get your period early or later than expected.


It’s a medical condition in which the uterus-like tissue grows outside the uterus. Normally, the endometrial tissue lines the inside of the uterus and thickens and sheds during the menstrual cycle, resulting in menstruation. In endometriosis, however, this tissue is found in other areas of the pelvis and sometimes beyond. It will cause early bleeding, making your period arrive on the date it wasn’t expected.
Medical attention by your healthcare provider will help you treat this condition.

Intense exercise

Exercise, to a limited extent as usual, is considered healthy and will positively boost your health and energy levels. However, intense exercise can disrupt hormonal balance and lead to changes in the menstrual cycle. This phenomenon is often referred to as “exercise-induced amenorrhea” or “athletic amenorrhea.”. It can either give you an early period or later than expected. 

Note: It should be noted that every individual engaging in physical activity might experience changes in their normal hormonal cycle, which is perfectly normal. It’s only concerning if it persists. 


Stress and hypertension can both affect the overall health negatively and will affect the body beyond your area of focus. One of the effects is a disturbed menstruation cycle. It happens when hormonal changes occur in the body due to stress, causing a change in reproductive hormones as well, which leads to an early or delayed period. 

Understanding your body’s stress triggers and learning their management is important.

Hormonal birth control

Hormonal birth control is mainly the medication that is taken as a contraception to avoid pregnancy. Some work by not implanting the fertilized egg, and some work by detaching the fertilized embryo by changing the hormone levels.

They change the hormone levels, which leads to early bleeding most often. You might notice an early spotting followed by a period at an unexpected time after 2-4 days of taking the hormonal birth control pills.

Uncontrolled or undiagnosed diabetes

It is also one of the most common causes of early periods as high levels of insulin in the case of diabetes will interact with hormones responsible for regulating the menstruation cycle, leading to early or late periods. It will happen consistently and needs medical attention for the proper diagnostic lab tests and prescriptions.

Thyroid disease

Thyroid disease, especially Hyperthyroidism, can change your normal menstrual cycle in a way that is in case of hyperactivation and stimulation of the thyroid gland. It leads to the increased release of thyroid hormone in the blood, which directly affects the menstrual cycle. it will directly affect your menstrual cycle and help regulate.

When to consult a doctor

Getting periods early rarely is not troubling. It is caused by the hormonal or diet changes. It is only troubling and needs medical attention if it occurs more often, and most importantly, the cycle of 20-21 days stays incomplete (the gap between the last and first period) as the causes of this vary. It’s good to seek medical attention before any of the cause intensifies.

Consult healthcare providers now for any query related to your period for customized prescriptions.

FAQs About Early Puberty Answered by Your Doctors Online Team

What are the signs of early puberty, girl?

Precocious puberty symptoms include the development of the following before the defined age:
Breast Growth and first period in Girls
Pubic or underarm hair
Rapid growth spurt
Body odor

What does it mean if you hit puberty early?

Mostly, early puberty may occur for no known reason. It tends to run in families. However, a problem in the brain, such as an injury, a tumor, or an infection, may be a cause in some cases. Other causes include pain in the sex glands, thyroid, or adrenal glands.

What foods cause early puberty?

High intake of proteins, meat, and processed food all tend to cause early puberty. 

My daughter got her period at 10. Will she still grow?

Yes, she will. Usually, the growth of the body, especially in terms of height, gets affected, and only the two years after the girl gets her period will be the time of growth (usually 2-3 inches max). After two years, you won’t see any noticeable changes in height. In terms of body growth, yes. Your daughter will not only grow physically but there will also be major changes in the psychological state as well.

Could I be pregnant if my period came early?

Usually, if you get pregnant, you won’t have your period, and it’s one of the signs you need to get the pregnancy check. Getting your period early means there is no existing pregnancy, and you can get pregnant.

Your Doctors Online uses high-quality and trustworthy sources to ensure content accuracy and reliability. We rely on peer-reviewed studies, academic research institutions and medical associations to provide up-to-date and evidence-based information to the users.

  • Loughnan, Libbet, et al. “Monitoring Menstrual Health in the Sustainable Development Goals.” The Palgrave Handbook of Critical Menstruation Studies (2020): 577-592.
  • Tarini, Ni Wayan Dewi, Wayan Sugandini, and Ni Komang Sulyastini. “Prevalence of anemia and stunting in early adolescent girls.” 3rd International Conference on Innovative Research Across Disciplines (ICIRAD 2019). Atlantis Press, 2020.
  • Sommer, Marni, et al. “Early adolescence in Madagascar: girls’ transitions through puberty in and out of school.” The Journal of Early Adolescence 40.3 (2020): 354-376.
  • Ncube, Nolwazi Nadia. “Ndebele Girls as Knowers: Menstrual Preparation and Sanitary Preferences in Zimbabwe.” Girlhood Studies 16.1 (2023): 54-70.

Get started today

Talk to online doctors now and get medical advice, online prescriptions, and referrals within minutes. On-demand healthcare services at your fingertips.

talk to online doctor 24/7 free