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Are you worried because your period has come a few days before expected?
Don’t worry, it’s more common than you think! In fact, up to 69% of women have cycles that vary by up to 6 days.
Lifestyle factors like diet, exercise, and stress commonly impact your menstrual cycle. Other times underlying health conditions like PCOS or a thyroid disorder may cause your period to come early.
Usually, an early period is not a cause for concern if it’s a one-off occurrence. But read on to learn more about the most common causes of an early period.
What is an early period?
A period is considered “early” if menstrual bleeding begins within 21 days of your previous period.
This is because the typical cycle length is between 21-35 days.
So if have a 32-day cycle one month and a 27-day cycle the next – don’t worry, that’s totally normal!
Check out this table that breaks down when an early period is normal vs. when you may want to consult your doctor:
As you can see, the occasional early period is not a cause for concern. However, if it’s happening more and more often, it could indicate a deeper issue. Now, let’s look at the most common causes for getting your period early.
Causes of early periods
There is a slew of possible causes for early menstruation including:
- Incorrect calculation
- Implantation bleeding
- Hormonal birth control
- Puberty
- Perimenopause
- PCOS
- Endometriosis
- Thyroid disorder
- Excessive exercise
- Disrupted circadian rhythm
Read on to learn how each of these can cause early periods.
Incorrect calculation
Sometimes you may simply get your dates mixed up. This can easily happen if you have irregular cycles or if you haven’t been tracking your cycles regularly.
There are many period tracking apps that you may consider using to take the guesswork out of tracking your cycle. Such tracking apps can provide you with accurate predictions of your cycle based on your past data and patterns. This makes it less likely your dates will get mixed up in the future.
Implantation bleeding
Have you heard of implantation bleeding? It’s almost like a sneak peek into what’s coming next!
You may notice a few spots of blood in your undies, but this isn’t a period. Rather, it’s the result of a fertilized egg attaching to the uterine lining. It typically happens around 6-12 DPO and occurs because uterine blood vessels can be damaged when the embryo implants into the uterine wall.
Implantation bleeding differs significantly from period bleeding. It is usually light and only lasts for up to 2 days. It is typically pinkish or brown.
You may experience other symptoms like:
- Light or faint cramps
- Mood swings
- Nausea or vomiting
- Increased breast sensitivity or breast tenderness
- Lower back pain
- Headaches
If you think you may be experiencing implantation bleeding, take a pregnancy test the day after your expected period to confirm your pregnancy.
Interested in learning more about implantation bleeding vs. period bleeding? Read our blog here.
Or, you can also check out this video below:
Hormonal birth control
If you are on hormonal birth control, you may experience light bleeding outside your scheduled period. This spotting outside your period is referred to as “breakthrough bleeding” and may be mistaken for an early period.
You may experience breakthrough bleeding if any of the following applies to you:
- You started birth control in the last 3-6 months
- You recently switched birth control
- You forgot to take your birth control pills or you don’t take them regularly
- You used an emergency birth control like Plan B
Puberty
Young girls typically have their first period around the age of 12-13.
During puberty, the process that regulates the menstrual cycle, known as the hypothalamus-pituitary-ovarian axis, is still immature.
The adjustment period can cause periods to be irregular, early, or late. 60-80% of cycles become regular in about 3 years.
Perimenopause
Perimenopause is the transitional period before your body reaches menopause. It is usually seen in women 45-55 years old, although it could happen sooner or later.
One of the most common symptoms of perimenopause is irregular periods. This may cause your period to come earlier or later than you expect.
This is due to massive hormone fluctuations during this time. Your FSH and LH increase and your estrogen and progesterone decrease. This can make your cycles shorter or longer and can cause your flow to be heavier or lighter.
You may have shorter cycles, which leads to an early period, because of a decline in ovarian reserve.
Irregular cycles can also be accompanied by the following symptoms:
- Hot flashes
- Mood changes
- Sleep disturbances
- Vaginal dryness
PCOS
Polycystic ovary syndrome (PCOS) is a hormonal disorder that causes the ovaries to produce an excess amount of androgen hormones.
PCOS affects 8-13% of women and is the leading cause of infertility. If you have polycystic ovary syndrome then you may often struggle with anovulatory cycles. These are cycles where you do not ovulate. Research shows that 90-95% of women with anovulatory infertility have PCOS.
The hormonal imbalances and struggles with ovulation can lead to irregular and early periods.
PCOS can cause the following symptoms:
- Irregular periods
- Acne
- Weight gain
- Excessive body hair growth
Learn more: PCOS And Pregnancy: All You Need To Know
PCOS and anovulatory cycles can make tracking your menstrual cycle and getting pregnant more difficult. But using the Inito Fertility Monitor can be a game changer.
Inito tracks four key fertility hormones – LH, estrogen, PdG (a urine metabolite of progesterone), and FSH.
Inito tracks and monitors LH, estrogen, and FSH to predict your fertile window. This means you’ll know the best days out of the month to have sex to increase your chances of getting pregnant.
Inito also tracks and measures PdG to confirm ovulation. This means you won’t have to spend any more time second-guessing if you actually ovulated or not.
Learn more about Inito here to see how it can help you understand your cycle better and increase your chances of conceiving.
Endometriosis
Endometriosis is a gynecological condition where the inner uterine tissue (a.k.a. endometrial tissue) grows outside the uterus.
This can lead to symptoms such as:
- Irregular periods
- Heavy periods
- Bleeding in between periods
- Severe abdominal pain
- Painful periods
Bleeding in between periods can easily be confused with a period.
Additionally, there is often more tissue to shed with each cycle. This may cause your period to come early and be accompanied by heavy bleeding.
Learn more: Getting Pregnant With Endometriosis
Thyroid disease
Your thyroid gland plays a critical role in the regulation of your metabolism and hormones. It directly affects the production, transport, and elimination of estrogen and progesterone.
Thyroid hormones are also involved in the growth of ovarian follicles. These follicles secrete hormones that affect the menstrual cycle.
When thyroid function is disrupted, it can throw your menstrual cycle off. This may cause you to have shorter or longer cycles.
Stress
Stress is not good for any part of your body. And your menstrual cycle is no exception.
Acute stress can have an unfortunate domino effect that results in early ovulation.
Here’s how:
- During stress, you release a hormone called cortisol (“stress hormone”).
- When your cortisol levels increase, so do your LH levels.
- This premature surge in your LH results in early ovulation.
- Early ovulation results in an earlier period.
High cortisol levels also cause progesterone levels to decrease. Since progesterone is one of the key reproductive hormones that regulates your menstrual cycle, this can lead to an irregular cycle.
Learn more: Low Progesterone: All You Need to Know
Excessive exercise
Exercise is great for you in moderation. But excessive exercise can actually negatively impact your menstrual cycle.
Excessive exercise suppresses the hypothalamus. This is an area of the brain that produces hormones such as FSH and LH. Since exercise suppresses the hypothalamus it lowers the production of FSH and LH.
Also, excessive exercise over time reduces the amount of fat in the body which results in lower estrogen levels.
Disruption of the circadian rhythm
Your circadian rhythm (your body’s “internal clock”) is closely related to your menstrual cycle. Disruption of your circadian rhythm can cause menstrual irregularities.
This can happen if you work the night shift or if you recently traveled to an area with a different time zone.
Should I be worried about early periods?
You probably don’t need to be worried if your early period is a one-off occurrence
However, if you regularly have cycles less than 21 days, you should see a doctor. Especially if you have any of the following symptoms:
- Heavy bleeding
- Severe pain, including pelvic pain
- Signs of too much androgen hormone such as facial hair, acne, body hair, loss of scalp hair, or infertility
You could mistake implantation bleeding for an early period, so you may want to take a pregnancy test to rule out pregnancy.
Tips for improving your early periods
To treat early periods that occur regularly, work with your physician to identify what the root cause is. They will explore treatment options based on your specific circumstances.
Early periods that occur occasionally usually aren’t a huge concern but could be the result of a hormonal imbalance.
Here are lifestyle modifications you can implement to decrease the chance of early periods caused by a hormonal imbalance:
- Eat a balanced diet – eat foods that help improve insulin sensitivity like complex carbs, lean meats, and fiber
- Exercise – Incorporate 30-60 minutes of moderate intense exercise per day. (More than 60 minutes of exercise per day can increase your risk of anovulation.)
- Manage stress – Try activities like yoga, meditation, and deep breathing to reduce your stress levels
- Prioritize sleep – Try to get 8 hours of sleep per night and avoid disrupting your circadian rhythm. Research has shown that good sleep positively affects the menstrual cycle:
– FSH is 20% higher in women who sleep for longer hours.
– Estradiol is 60% lower in women who have regular sleep schedules.
– Mean luteal progesterone levels increase by 9.4% for every hour increase in daily sleep duration. - Track your cycles with Inito to get a full picture of your hormones, and track and confirm ovulation.
Key Takeaways:
- An early period occurs within 21 days before your next period.
- Early periods are not usually a cause for concern.
- Regular early periods could indicate an underlying condition, and you should consult your doctor.
- You could mistake implantation bleeding for your period. Implantation bleeding usually occurs around 6-12 DPO and is caused by an embryo attaching to the uterine lining. Take a pregnancy test the day after your expected period to rule out or confirm if you are pregnant.
- Medical conditions like endometriosis, PCOS, and thyroid disorders can cause early periods.
- Puberty and perimenopause cause hormonal fluctuations which can cause early periods.
- Lifestyle habits can affect your periods. Too much stress or strenuous exercise can result in early periods.
- Eat a healthy diet, exercise consistently, and manage your sleep and stress levels to reduce the occurrence of early periods.
FAQs
Some possible causes of an early period include the following:
- Incorrect calculation
- Implantation bleeding
- Hormonal birth control
- Puberty
- Perimenopause
- PCOS
- Endometriosis
- Thyroid disorder
- Excessive exercise
- Disrupted circadian rhythm
The number of tests depends on the irregularity and length of your cycles. For someone with an average cycle length of 30 days, 12-15 tests may be required to track and confirm ovulation.
The number of tests depends on the irregularity and length of your cycles. For someone with an average cycle length of 30 days, 12-15 tests may be required to track and confirm ovulation.
The number of tests depends on the irregularity and length of your cycles. For someone with an average cycle length of 30 days, 12-15 tests may be required to track and confirm ovulation.
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- Menstrual Cycle Length and Patterns in a Global Cohort of Women Using a Mobile Phone App: Retrospective Cohort Study
- The Normal Menstrual Cycle and the Control of Ovulation – Endotext – NCBI Bookshelf
- Unscheduled bleeding and contraceptive choice: increasing satisfaction and continuation rates – PMC
- Polycystic ovary syndrome
- Perimenopausal Bleeding and Bleeding After Menopause | ACOG
- Menstrual cycle length variation by demographic characteristics from the Apple Women’s Health Study | npj Digital Medicine
- Acute stress may induce ovulation in women – PMC
- Menstrual cycle effects on sleep
- Effect of Exercise on Ovulation: A Systematic Review | Sports Medicine
- Impact of sleep patterns upon female neuroendocrinology and reproductive outcomes: a comprehensive review
