Hello,
Welcome to the ehealthforum and I am glad to help you out. The common causes of this irregularity in periods needs to be probed. High levels of stress, cholesterol, hormonal imbalance, chain smoking and dramatic changes in your life style may be some of the common causes of your irregular periods.
Other causes include medical conditions like PCOS and fibroid uterus. PCOS is diagnosed by blood tests like blood insulin levels, serum testosterone and androgen levels and ultrasound. Fibroids are benign tumors of the uterus. They are diagnosed by ultrasound lower abdomen or CT abdomen.
Please consult a gynecologist and get yourself thoroughly examined to diagnose the cause of irregular periods and start with the treatment. It is very difficult to precisely confirm a diagnosis without examination and investigations and the answer is based on the medical information provided. For exact diagnosis, you are requested to consult your doctor. I sincerely hope that helps. Take care.