Your menstrual cycle can tell you a lot about your health and fertility. Regular cycles usually mean you are ovulating regularly, while irregular cycles can be a sign of a condition worth checking, especially if you are trying to conceive.
How to tell if your cycles are regular
Track your periods for at least three months. Count from the first day of one period to the day before the next. A calendar or period-tracking app makes this easy. Note how long bleeding lasts and how heavy it is.
What is a normal cycle length?
- A normal cycle lasts between about 21 and 35 days
- Bleeding usually lasts two to seven days
- Cycle length varies a little from month to month, and a difference of a few days is normal
Cycles are considered irregular if their length varies widely from month to month, if they are shorter than 21 days or longer than 35 days, or if periods stop for three months or more. Learn more about the phases of the menstrual cycle.
What causes irregular cycles?
- PCOS (polycystic ovary syndrome)
- Thyroid problems or a raised prolactin level. See hormonal assays
- Significant weight gain or loss, or excessive exercise
- Stress and illness
- Breastfeeding, and the years leading up to menopause
- Some medicines and contraceptives
Irregular cycles and fertility
If ovulation is irregular, it is harder to time intercourse and there are fewer chances to conceive each year. Many causes of irregular cycles are treatable, for example with medicines to help ovulation. See what is normal fertility?
When to see a doctor
- Your cycles are shorter than 21 days or longer than 35 days
- Your periods have stopped for three months or more
- Bleeding is very heavy or very painful. See painful periods and infertility
- You bleed between periods or after intercourse
- You have been trying to conceive without success
Frequently asked questions
Is a 40-day cycle normal?
Cycles longer than 35 days are usually considered irregular and may mean ovulation is not happening every month. It is worth checking with a doctor.
Can I get pregnant with irregular periods?
Yes, but it may take longer. Treatment to help ovulation can improve the chances.
Does stress affect periods?
Yes. Significant stress can delay or stop ovulation and periods.
If you have questions about your own situation, you can meet our doctors at our Basavanagudi, Koramangala and Ballari centres, or contact us to book an appointment.
This article is for general information and does not replace medical advice. Treatment decisions should be made with a qualified doctor who knows your history.