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Are you worried because your period has come a few days before expected?
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. Read on to learn more about the most common causes of early periods and when you should get worried about them.
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.
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:
How early did you get your period? | Is it normal or not? |
1-7 days early | Normal |
>7 days early | One-off incidence = normal. Happens for more than 3 cycles and is accompanied by other symptoms = could be an underlying issue |
As you can see, the occasional early period is not a cause for concern. However, if it’s happening more frequently, it could indicate a deeper issue. Let’s examine the most common causes of early menstruation.
Causes of Early Periods
There is a slew of possible causes for early menstruation, including:
- Puberty
- Perimenopause
- PCOS
- Endometriosis
- Thyroid disorder
- Excessive exercise
- Disrupted circadian rhythm
Read on to learn how each of these can cause early periods.
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 typically seen in women aged 45-55 years old, although it can occur at a younger or older age.
One of the most common symptoms of perimenopause is irregular periods. This may cause your period to occur earlier or later than expected.
This is due to the massive hormone fluctuations that occur during this time. Your FSH and LH increase, and your estrogen and progesterone decrease. This can cause your cycles to be shorter or longer, and may result in heavier or lighter menstrual flow.
Due to a decline in ovarian reserve, you may experience shorter cycles, which can lead to an early period.
The following symptoms can also accompany irregular cycles:
- 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 anovulation or 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 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 to see how it can help you understand your cycle better and increase your chances of conceiving.
Know your chances of Ovulation!
Take our ovulation quiz to understand how your hormone patterns and
lifestyle factors may affect your chances of ovulating
Endometriosis
Endometriosis is a gynecological condition in which 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 a decrease in progesterone levels. 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. However, 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.
What's Not an Early Period (But Often Seems Like One)?
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
Implantation bleeding means you see a few blood spots in your undies, but this isn’t a period. It results from a fertilized egg attaching to the uterine lining, typically around 6-12 DPO (Days Past Ovulation). It 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.
Here are a few other implantation symptoms to help you differentiate implantation bleeding from periods.
You may experience other symptoms like:
- Light or faint cramps
- Mood swings
- Nausea or vomiting
- Increased breast sensitivity or breast tenderness
- Lower back pain
If you think you may be experiencing implantation bleeding, take a pregnancy test the day after your expected period to confirm your pregnancy.
To learn more about implantation bleeding, 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 apply 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
Should I Be Worried About Early Periods?
You probably don’t need to be worried if your early period is a one-off occurrence
You probably don’t need to be worried if your early period is a one-off occurrence.
However, you should see a doctor if you regularly have cycles less than 21 days.
- 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 regular early periods, work with your physician to identify the root cause. They will then explore treatment options based on your specific circumstances.
Early periods that occur occasionally are usually not a huge concern, but they 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 moderately intense daily exercise. (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 – Use apps like Inito to get a full picture of your hormones, and track and confirm ovulation.
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.
There are a few different causes for early periods. Some of these include:
- Puberty (periods during the years of puberty are more irregular)
- Perimenopause (your cycle length tends to shorten)
- Underlying conditions like PCOS, endometriosis, or thyroid disorders
- Too much stress or exercising too much (both mess with your hormonal balance)
- Having a disrupted circadian rhythm (often due to sleep schedules or traveling between time zones)
Yes, an early period could potentially mean pregnancy, but it wouldn’t truly be considered a period then. Some women who experience implantation bleeding (which is around 1 in 4), may mistake implantation spotting for an early period. Implantation bleeding would happen a few days before Aunt Flo is expected, but it would be much lighter and shorter-lived than a regular period.
Know more: Implantation Bleeding vs. Periods: How to Distinguish?
The amount of days of early period that would be considered normal depends on whether you mean how many days the early period lasts or how many days early it is. If you occasionally notice your period coming a few days to a week early, it could be normal and nothing to worry about. And any period that lasts between 2 – 8 days is usually considered normal (if it’s a typical amount of bleeding). That said, if your period begins coming early regularly, it could be a sign that something is up. And if your period is shorter than 2 days or longer than 8 days, it may also be a signal that something is going on.
So if it’s only a one-time thing, track your symptoms and see if things go back to normal next cycle. If you continue to notice changes with your period or you’re concerned, check in with your healthcare provider!
A period that could be considered as early pregnancy would be implantation bleeding. This isn’t a true period and would be noticed 6-12 days past ovulation. Implantation bleeding happens in about 25% of pregnancies and looks like light pink or brown spotting that lasts for several hours up to a day or two.
There’s no surefire way to tell the difference between early pregnancy vs. your period coming. This is because many of the symptoms of early pregnancy overlap with normal luteal phase symptoms (both are caused by rising progesterone levels).
That said, here are some potential ways you may be able to distinguish the two:
- You have an “early period” that is more like short-lived spotting (this could be implantation bleeding)
- Your PMS symptoms feel more extreme and noticeable than usual (like extreme fatigue or extreme bloating)
- You have increased vaginal discharge that looks creamy in texture
- You have any other symptoms that you don’t typically experience prior to your period
Keep in mind that these are only potential signs. The only way to truly tell the difference is through taking a pregnancy test after a missed period.
Know more: Implantation Bleeding vs. Periods: How to Distinguish?
It is not considered healthy to get periods early on a regular basis, but if you get an occasional early period, it’s probably nothing to worry about. A normal cycle length can be anywhere from 21 – 35 days, so if it’s normal for you to have periods that are on the lower end of that range, that’s okay. But if you notice that your period is consistently coming earlier than usual, you may want to check in with your doctor to see what could be going on!
It is considered okay if your period comes early every now and then. But if you have consistently early or irregular periods, it could be an indication that something is going on with your hormones or that you have an underlying condition that needs to be addressed. The best thing to do is to track your cycle each month so you can recognize what’s out-of-the-norm for you and consult your doctor when you have concerns.
There are a few reasons you could have a period coming a week early. If this happens only on occasion, it could simply be a minor fluctuation in your hormones. Other factors that can lead to getting a period that comes a week early include:
- Going through puberty or perimenopause (when cycle lengths and frequencies or more irregular)
- Having an underlying condition such as endometriosis, a thyroid disorder, or PCOS
- Excessive exercise
- Stress or a disrupted circadian rhythm
It’s also possible that you are not actually experiencing a real period but either implantation bleeding or abnormal mid-cycle bleeding.
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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
