Symptom Guide · Irregular Periods
Why are my periods irregular?
A period that's a bit early or late once in a while is normal. But if your cycles are always shorter than 21 days, longer than 35 days, or totally unpredictable, your body is telling you something — and it is worth finding out what.
Short answer
A normal cycle is 21 to 35 days. Your periods count as irregular if the gap keeps changing by more than a week, your cycle falls outside that range, or you skip periods without being pregnant — most often caused by PCOS, thyroid problems, stress, or perimenopause.
What counts as an irregular period?
A normal cycle is 21 to 35 days, counted from the first day of one period to the first day of the next. Your cycle is irregular if it's often outside this range, if the gap between periods keeps changing by more than a week, or if you skip periods and you're not pregnant.
What are the most common causes of irregular periods?
In young women, PCOS (polycystic ovary syndrome) is the most common cause — it affects about 1 in 5 Indian women. Other common causes are thyroid problems, a lot of stress, sudden weight gain or loss, too much exercise, breastfeeding, and some medicines. In women over 40, irregular cycles are often the first sign of perimenopause.
Can stress really delay my period?
Yes. Stress hormones interfere with the signals between your brain and ovaries that control ovulation. A stressful month can delay your period by days or even weeks. But if your periods stay irregular for more than two or three cycles, don't keep blaming stress. Get checked — treatable conditions like PCOS and thyroid problems cause the same pattern.
What tests will the doctor do for irregular periods?
Usually, the doctor asks about your health, does a pelvic ultrasound, and orders blood tests — thyroid, prolactin, and hormones like LH, FSH, and testosterone. This finds the cause in most cases. Treatment then depends on the cause: cycle-regulating medicine, thyroid treatment, lifestyle changes, or fertility care if you're trying to conceive.
Can I get pregnant with irregular periods?
Yes, though it may take longer because ovulation is unpredictable. If your cycles are irregular and you've been trying for six months or more, see a gynecologist. Once we know the cause, making ovulation regular again is often straightforward.
See a doctor promptly if you have
- No period for 3 months or more (and you are not pregnant)
- Cycles consistently shorter than 21 days
- Bleeding between periods or after intercourse
- Irregular periods along with acne, excess facial hair, or rapid weight gain
- Irregular periods while trying to conceive
This page is general information, not a diagnosis. Only a consultation and examination can tell you what is causing your symptoms.
Worried about this symptom?
Consult Dr. Madhumita Das Mazumdar — MD (OBG), 30+ years of experience — at the clinic in Beltola, Guwahati, or on WhatsApp from anywhere.