Perimenopause cycle change tracker
Cycles often get shorter, then longer and more erratic before the menopause. Add your recent period dates to see your own pattern.
Your details
From your dates
28, 36, 29, 45
days between periods
- Biggest change between cycles16 days
- Longest gap45 days
- PatternCycles changing by 7 days or more
Repeated swings like this fit the early menopausal transition. Staging is a research tool; symptoms and how you feel matter more, and your GP can talk through what is happening.
Bleeding after 12 months without periods, bleeding between periods or after sex, or very heavy bleeding: see your GP promptly.
The working
Swings between cycles
Gaps of 28, 36, 29 and 45 days change by 8, 7 and 16 days from one cycle to the next. STRAW+10 describes repeated swings of 7 days or more as the early menopausal transition, and a gap of 60 days or more as the later stage.
Typical pattern
How cycles change
| Stage | What you might notice |
|---|---|
| Late reproductive years | cycles a little shorter |
| Early transition | cycles vary by 7 days or more |
| Late transition | gaps of 60 days or more |
| Menopause | 12 months with no period |
Contraception
Still needed
You can still get pregnant in the perimenopause. The NHS advises contraception until 2 years after your last period if under 50, or 1 year if over 50.
Read with care
What this cannot tell you
- DiagnosisChanging cycles have other causes too.
- Bleeding problemsVery heavy or irregular bleeding needs checking.
- Hormonal methodsContraception and HRT change bleeding patterns.
Questions
Common questions
How do periods change in perimenopause?
Often shorter at first, then longer, heavier or more erratic.
How long does perimenopause last?
On average about 4 years, but it varies a lot.
Can I get pregnant during perimenopause?
Yes, so contraception is still needed.
Sources
- Harlow SD et al. Executive summary of STRAW+10: staging reproductive aging. Menopause 2012
- NICE NG23: menopause, identification and management
- NHS: menopause
Last checked 21 October 2026. Spotted something wrong? Tell us and we will fix it.
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