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Irregular Periods with PCOS

Polycystic ovary syndrome is one of the most common causes of irregular periods. Here's how PCOS affects your cycle, what to track, and how to identify patterns even without regular periods.

Medical disclaimer

This content is for informational purposes only and is not a substitute for professional medical advice, diagnosis, or treatment. Dawn Phase is not a medical device. Always consult a qualified healthcare professional with questions about your health.

What causes it

PCOS involves elevated androgens (testosterone), insulin resistance, and disrupted follicle development. Multiple follicles begin developing but often none reach maturity and rupture — so ovulation doesn't occur. Without ovulation there is no progesterone, oestrogen continues to stimulate the uterine lining unchecked, and eventually a period occurs — but the timing is unpredictable. Cycles can range from 35 to over 90 days, or periods may be absent for months.

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How to track it

Log every period start date, cycle length, flow characteristics, and daily symptoms. With PCOS, symptom patterns — acne flares, energy dips, weight fluctuations, mood changes — may be more informative than cycle timing. Tracking for 6–12 months builds a picture of your individual PCOS pattern. Export this data as a CSV before GP appointments — it's far more useful than trying to recall dates.

When to see a doctor

See a doctor if you are missing periods consistently (more than 3 in a row), if you have symptoms of high androgens (unwanted hair growth, scalp hair loss, persistent acne), if you are trying to conceive, or if you have been diagnosed with PCOS and are not being monitored. Long-term anovulation without progesterone can increase the risk of endometrial hyperplasia.