Perimenopause periods: a period every 2 weeks, heavy bleeding and when to worry
By Softer Mind · Updated 15 October 2026 · 8 min read · Based on NHS guidance and published research
Your period used to turn up like clockwork. Now it arrives after two weeks, then disappears for two months. Or it comes so heavily that you plan your day around the nearest loo, and you lie awake worrying about leaks.
If you're in your 40s, changes like these are often part of perimenopause. A perimenopause period every 2 weeks, heavy periods and long gaps are all common. The NHS says that in perimenopause, periods may come more often or less often, and bleeding may get heavier or lighter.
But common doesn't mean you should just put up with it. Some changes are worth checking with a GP, and a few need help quickly. This page explains what's usual, what isn't, and what can help.
See your GP if:
- you're flooding (bleeding through your pad or tampon onto clothes or bedding), or changing protection every 1 to 2 hours
- you pass clots bigger than about a 10p coin
- you often feel tired, faint, dizzy or short of breath, which can be signs of anaemia
- you bleed between periods or after sex
- your bleeding is heavier than it used to be, or a period lasts more than 7 days
- you have any bleeding after 12 months or more with no period, even once. See bleeding after menopause
Get urgent help: call 111 if you're bleeding very heavily and feel faint, dizzy or very breathless. Call 999 if you collapse or it feels like an emergency. Ask for an urgent GP appointment or call 111 if you've missed a period and have unusual bleeding with pain low in your tummy, as this can be a sign of an ectopic pregnancy.
Is it normal to have a period every 2 weeks in perimenopause?
It can be. Perimenopause is the time when your periods become irregular, and the gaps between them can get shorter as well as longer.
The NHS counts periods as irregular when the gap between them is less than 21 days or more than 35 days. It says irregular periods are more likely as you near menopause.
Menopause researchers describe perimenopause in two stages. In the early stage, the length of your cycle starts to vary by 7 days or more from one cycle to the next. In the late stage, you start to go 60 days or more without a period. These definitions come from STRAW+10, which estimates that the late stage lasts 1 to 3 years on average.
So periods close together, then far apart, is a familiar pattern. But the NHS says to see a GP if your periods are irregular. It's worth a chat, especially if periods every 2 weeks go on for a few months. Bleeding that often means losing more blood overall, and that can leave you short of iron.
Heavy periods in perimenopause
Heavy periods are one of the most common changes. The NHS says periods can get heavy as you approach menopause, and that heavy periods may be normal for you. Treatment can help if they're affecting your life.
The NHS lists these signs of heavy periods:
- changing a pad or tampon every 1 to 2 hours
- needing two kinds of period product at once
- periods lasting more than 7 days
- passing clots bigger than about 2.5cm (roughly a 10p coin)
- bleeding through to your clothes or bedding
- avoiding things you'd normally do, or taking time off work
- often feeling tired or short of breath
A leaflet from the Royal Wolverhampton NHS Trust adds flooding even with pads or tampons, and needing to change in the night. It says some women only have heavy periods at certain times of life, such as in the year or so before the menopause.
The NHS menopause page is clear on one point: see a GP if you're bleeding more, not less, than before.
Bleeding for 3 weeks or longer
Long periods are common in perimenopause. A large US study called SWAN followed 1,320 women aged 42 to 52 using daily period diaries (Paramsothy and others, 2014). Over the study:
- about 78% had periods lasting 10 days or more, at least three times
- about 67% had 6 or more days of spotting, at least three times
- about 35% had periods with 3 or more days of heavy bleeding, at least three times
That's reassuring in one way: long and heavy bleeds are a normal part of the picture for many women. But the researchers say they couldn't tell which bleeds had a medical cause. So these figures can't tell you that your own bleeding is fine.
The NHS says to see a GP if a period lasts longer than 7 days. Bleeding for 3 weeks is well past that, so please book an appointment.
Why do periods change in perimenopause?
Near the menopause, your ovaries don't always release an egg each month. The Wolverhampton leaflet explains that when this happens, periods can become irregular or stop for a while, and when they do come they tend to be heavy. It says this is more common in women who are near the menopause.
Because this doesn't happen in a steady monthly pattern, your periods can change from one month to the next. That's why one period can be short and light and the next long and heavy.
What else can cause period changes?
Don't assume it's all perimenopause. The NHS lists other causes of heavy, irregular or extra bleeding:
| Possible cause | What it can do |
|---|---|
| Fibroids, adenomyosis or endometriosis | Heavy periods |
| Small growths in the womb, such as polyps | Heavy periods, or bleeding between periods |
| Thyroid problems | Irregular periods |
| Hormonal contraception, such as the pill, the injection or a hormonal coil | Irregular bleeding or spotting |
| Sexually transmitted infections, such as chlamydia | Bleeding between periods or after sex |
| Bleeding disorders, or some medicines that thin the blood | Heavy periods |
| Stress, big weight changes, or exercising a lot | Irregular periods |
| Pregnancy | A missed or unusual period |
| Womb cancer (rare) | Heavy periods, or bleeding between periods |
Sources: the NHS pages on heavy periods, irregular periods and bleeding between periods or after sex.
The NHS says bleeding between periods or after sex can sometimes be a sign of cancer, which is why it should always be checked. Checking early is the point, not a reason to panic.
Can you still get pregnant in perimenopause?
Yes. The NHS says it's possible to get pregnant during perimenopause, so you still need contraception:
- for 2 years after your last period, if you're 40 to 49
- for 1 year after your last period, if you're 50 or over
If your periods are irregular, a missed or odd period could be pregnancy. If there's any chance, do a pregnancy test.
What can help with heavy or irregular periods?
Keep a record. The NHS suggests using an app or a diary, counting day 1 as the first day of your period. Note how many days you bleed, how often you change protection, any clots or flooding, and any bleeding between periods or after sex. This makes it much easier for a GP to see what's going on.
Plan for heavy days. Keep spare protection and a change of underwear in your bag.
Notice how you feel. Tiredness, breathlessness or feeling dizzy can be signs that you're low in iron. Mention them to your GP rather than pushing through.
Things to talk to your GP about
Your GP will usually ask about your bleeding and may examine you. The NHS says you may have a blood test to check for iron deficiency anaemia. You may be referred for an ultrasound scan or a look inside the womb with a thin camera (hysteroscopy).
The NHS lists these treatments for heavy periods, which you can discuss with your GP:
- a hormonal coil (intrauterine system, or IUS)
- the combined contraceptive pill
- tranexamic acid, a medicine to reduce bleeding
- prescription anti-inflammatory painkillers
- for some women, a specialist procedure to remove the lining of the womb, or fibroids, or a hysterectomy
What suits you depends on the cause, and on whether you might want to get pregnant or need contraception. The Wolverhampton leaflet says not treating heavy periods is also an option, as long as there's no serious cause and the bleeding isn't making you anaemic.
Bleeding after your periods have stopped is different
Everything above is about bleeding while you're still having periods. Once you've gone 12 months or more without a period, things change.
The NHS says any bleeding after menopause should be checked by a GP, even if it's only a small amount or has only happened once. It's not usually serious, but it can be a sign of cancer. Your GP should refer you, and you should not have to wait more than 2 weeks to see a specialist.
So if you've had a year with no periods and then bleed or spot, don't wait to see if it settles. See our page on bleeding after menopause.
When to see your GP
Book an appointment if:
- your periods are heavier than before, or heavy periods are affecting your life
- you're having periods every 2 or 3 weeks for a few months
- a period lasts more than 7 days
- you bleed between periods or after sex
- you're often tired, breathless or dizzy
- you have any bleeding after 12 months with no period
If you're not sure whether your periods are a sign that perimenopause is nearly over, see our guide to the signs perimenopause is ending. Heavy periods can also leave you worn out, so our page on perimenopause fatigue may help.
You may also find these pages useful: perimenopause spotting, bleeding after menopause and the full list of perimenopause symptoms.
This page is general information, not medical advice. If you're worried about any symptom, please talk to your GP or pharmacist.