Irregular Periods in Perimenopause: What’s Normal and What’s Not

Educational information, not medical advice: see our Medical Disclaimer.

Irregular periods in perimenopause are common: a change in your periods is often the first sign. ACOG says cycles may become longer or shorter, you may skip periods, and the flow may get lighter or heavier (ACOG). Those changes are expected, but ACOG also says to report them to your health care professional, because abnormal bleeding may be a sign of a problem.

This guide covers what irregular periods usually look like in perimenopause, how cycle patterns point to early or late perimenopause, which bleeding patterns are worth getting checked, what else can change your periods, and why pregnancy is still possible. For the other symptoms, use our perimenopause symptoms checklist. If you’re not sure where you are in the transition, start with perimenopause vs menopause, or see our complete perimenopause & menopause guide for the full picture.

In this article:

• What Happens to Your Periods in Perimenopause
• Early vs Late Perimenopause: What Cycle Patterns Suggest
• What’s Common and What Deserves a Check
• Other Causes of Irregular Periods
• Do You Need a Test to Confirm Perimenopause?
• Can You Still Get Pregnant With Irregular Periods?
• How to Track Your Periods
• When to See a Doctor
• Irregular Periods in Perimenopause FAQ
• Your Next Step

What Happens to Your Periods in Perimenopause

The Menopause Society explains that the change in periods is caused by the ovaries’ erratic production of hormones and less frequent release of an egg (The Menopause Society). Mayo Clinic adds that as ovulation becomes more unpredictable, the time between periods may be longer or shorter, your flow may range from light to heavy, and you may skip some periods (Mayo Clinic). In some months the ovaries may release an egg, and in other months they don’t (ACOG). Changes you may notice include:

• Cycles that get shorter or longer, so periods come more or less often
• Skipped periods
• Flow that becomes lighter or heavier than you’re used to
• Cycle length that varies from one month to the next

The Menopause Society says the first changes are often subtle, such as cycles that become a little shorter than usual. Later, cycle length may vary by 7 days or more and periods may be skipped (The Menopause Society). One month can look very different from the next, which is why a single cycle rarely tells you much.

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Early vs Late Perimenopause: What Cycle Patterns Suggest

Clinicians use cycle patterns to describe where you are in the transition, based on a staging system called STRAW+10 (ASRM summary). Mayo Clinic and The Menopause Society describe it this way:

This is a rough guide, not a diagnosis, and it can’t tell you exactly when your last period will be. For how long each stage tends to last, see our article on how long perimenopause lasts.

What’s Common and What Deserves a Check

ACOG says changes in menstrual bleeding are normal during perimenopause, but you should still report them, because abnormal bleeding may be a sign of a problem (ACOG). Its bleeding guidance separates changes that fit the transition from bleeding that isn’t considered normal (ACOG).

Often part of the transition

• Cycles that are shorter or longer than before
• Skipped periods
• Bleeding that is lighter or heavier than before

Worth raising with a clinician

ACOG says it is not normal to have:

• Bleeding or spotting between periods
• Bleeding or spotting after sex
• Heavy bleeding during your period, including bleeding that soaks through one or more pads or tampons every hour
• Bleeding that is heavier than usual or lasts for more days than usual
• Any bleeding after menopause, meaning after 12 months without a period

ACOG’s general abnormal-bleeding definitions also include bleeding that lasts more than 7 days, cycles shorter than 21 or longer than 35 days, and going 3 to 6 months without a period (ACOG: abnormal uterine bleeding). Those last two aren’t perimenopause-specific cutoffs, because cycle changes and skipped periods are expected at this stage, but ACOG still advises talking with your ob-gyn about any abnormal bleeding. If your periods are coming about every two weeks, our guide to period every 2 weeks in perimenopause goes through the possible causes and what to track.

Other Causes of Irregular Periods

ACOG describes perimenopause as a diagnosis of exclusion, which means other conditions that can cause abnormal bleeding need to be ruled out first (ACOG). Causes ACOG lists include:

• Thyroid disorders, and high levels of the hormone prolactin (hyperprolactinemia)
• Problems with ovulation, including polycystic ovary syndrome (PCOS)
• Uterine polyps, fibroids or adenomyosis
• Infection
• Medications, including hormonal birth control, blood thinners and aspirin. The copper IUD can also cause heavier periods, especially in the first year (ACOG)
• Bleeding disorders, where the blood doesn’t clot properly
• Thickening of the uterine lining (endometrial hyperplasia) and, in some cases, endometrial cancer
• Causes related to pregnancy

Abnormal bleeding can be an early sign of endometrial cancer, which is one reason ACOG says to have it checked. Most cases occur in women in their mid-60s who are past menopause, and it is usually diagnosed at an early stage, when treatment is most effective (ACOG).

To find the cause, an ob-gyn reviews your personal and family health history and may do a physical exam and tests, such as blood tests, a pelvic ultrasound or an endometrial biopsy, which takes a small sample of the uterine lining (ACOG). Treatment depends on the cause. ACOG says polyps may be removed with a surgical procedure, for example, and endometrial hyperplasia can be treated with progestin therapy. For treatment of other perimenopause symptoms, see our guide to perimenopause treatment options.

Do You Need a Test to Confirm Perimenopause?

It depends on your age and on who you ask. The UK’s NICE guideline says perimenopause can be identified without laboratory tests in otherwise healthy people aged 45 or over who have menopause-associated symptoms, specifically hot flashes or night sweats that recently started along with any change in their menstrual cycle. It advises against using tests such as anti-Müllerian hormone, inhibin A or B and estradiol for this at that age, and suggests considering an FSH blood test only for people aged 40 to 45 with symptoms including a cycle change, or for people under 40 in whom menopause is suspected (NICE guideline NG23).

ACOG’s approach, as described by ob-gyn Dr. Esther Eisenberg, starts by ruling out other causes of abnormal bleeding with pelvic exams, blood tests and ultrasounds. If nothing is wrong, perimenopause is the likely explanation for irregular periods, especially for women in their 40s (ACOG). So the amount of testing can differ depending on your age, your symptoms and your clinician, and a clinician who knows your history is the best person to decide.

Can You Still Get Pregnant With Irregular Periods?

Yes. The Menopause Society says women in perimenopause can still get pregnant even when their cycles are irregular. If you don’t want a pregnancy, it advises using birth control until menopause is confirmed, meaning 1 year after your final period (The Menopause Society). Mayo Clinic gives the same advice (Mayo Clinic). The NHS gives age-based guidance: contraception for 2 years after your final period if you’re 40 to 49, or 1 year if you’re 50 or over (NHS).

Contraception can also change how your periods look. ACOG says hormonal birth control can cause changes in bleeding (ACOG), and NICE notes that it can be difficult to identify menopause in people taking hormonal treatments (NICE). Ask your clinician which method suits you. A missed period can also have more than one explanation, which is another reason to mention it.

How to Track Your Periods

The Menopause Society suggests tracking your bleeding on a calendar or smartphone app so it’s easy to review (The Menopause Society). Useful details to note:

• The first day of each period and how many days it lasts
• How heavy the flow is, including whether you’re soaking through a pad or tampon every hour
• Spotting between periods or after sex
• Other symptoms, such as hot flashes, sleep problems or mood changes (our symptoms checklist works as a template)
• Medicines, supplements and contraception you use

The more cycles you record, the easier it is to see a pattern, and the more useful your notes are at an appointment. Our guide to preparing for an appointment has more tips.

When to See a Doctor

ACOG says you should talk with your ob-gyn about any abnormal uterine bleeding, even when changes may be expected during perimenopause (ACOG). Talk to a doctor soon if:

• You’re soaking through one or more pads or tampons every hour. ACOG lists this as abnormal bleeding.
• Get emergency care if you’re changing pads or tampons every hour for more than 2 hours in a row and you also have chest pain, shortness of breath, or feel lightheaded or dizzy. ACOG says to seek emergency medical care right away.
• Your bleeding lasts more than 7 days, or you bleed or spot after sex or between periods.
• You still have periods but you’re bleeding more, not less, than before. The NHS says to contact a GP in that situation (NHS).
• You’ve gone 12 months without a period and then have any bleeding. Mayo Clinic says to talk to your healthcare professional right away (Mayo Clinic).
• You’re under 40 and your periods become irregular or stop. NICE recommends considering an FSH test in people under 40 in whom menopause is suspected (NICE).
• Your symptoms are affecting your sleep, work or daily life.

If you’re unsure, take your period log to the appointment.

Irregular Periods in Perimenopause FAQ

Is it normal to have two periods in one month in perimenopause?

Cycles can get shorter in perimenopause, so periods may come more often (ACOG). But bleeding between periods is on ACOG’s list of bleeding that isn’t normal, and it can be hard to tell a short cycle from spotting. A log with dates and flow helps your clinician tell the difference, and it’s worth raising if it keeps happening.

How long can you go without a period in perimenopause?

Mayo Clinic says that going 60 days or more between periods suggests late perimenopause (Mayo Clinic). Menopause is reached after 12 months in a row without a period. ACOG’s general abnormal-bleeding list includes going 3 to 6 months without a period (ACOG), and a missed period can have other explanations, including pregnancy, so mention long gaps to a clinician.

Are heavy periods normal in perimenopause?

Flow can get heavier or lighter (ACOG), but ACOG also lists heavy bleeding, bleeding that soaks through one or more pads or tampons every hour, and bleeding that is heavier or lasts longer than usual as not normal. Causes ACOG lists include fibroids, polyps and some medications, so it’s worth having heavy bleeding checked rather than waiting it out.

Do irregular periods mean I’m in menopause?

No. Menopause is confirmed after 12 months without a period (ACOG). Until then you’re still in perimenopause, or your irregular periods may have another cause. Our guide to perimenopause vs menopause explains the difference.

Can you still ovulate during perimenopause?

Yes, but not every month. ACOG says that in some months the ovaries may release an egg and in other months they don’t (ACOG). That is why cycles become unpredictable and why pregnancy is still possible.

Your Next Step

Start with a few weeks of notes: period dates, flow, spotting and other symptoms, using our perimenopause symptoms checklist as a guide. If anything on ACOG’s not-normal list sounds familiar, book an appointment rather than waiting it out. For related reading, see our guides on perimenopause vs menopause, how long perimenopause lasts and perimenopause treatment options, and everything in our perimenopause symptoms category.

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Sources: Perimenopausal bleeding and bleeding after menopause — ACOG · The Menopause Years — ACOG · Abnormal uterine bleeding — ACOG · My periods have changed. Is menopause around the corner? — ACOG · Perimenopause: symptoms and causes — Mayo Clinic · Perimenopause — The Menopause Society · Menopause symptoms — NHS · Menopause: identification and management (NG23) — NICE · STRAW+10 staging — ASRM · Featured image: Shixart1985 / Wikimedia Commons (CC BY 2.0)

About the author: Jessica Bordo writes Daily Health Cycle, where she shares practical, evidence-based women’s health information. Articles are informed by sources such as the NHS, CDC and Mayo Clinic, and we link to our main sources. No medical reviewer is listed for this article, so use it to prepare questions for your own clinician, not to replace their advice. Our authors page explains how we approach accuracy and disclaimers.

This article is for general education and isn’t medical advice. Read our Medical Disclaimer and talk with a qualified clinician about your own care.

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