Hello Thanks for writing to us with your health concern. The most possible cause of delayed periods in your case is the intake of the I pill. It can delay or prepone your cycles by a week, sometimes more, upto 10 days, so mostly the delay is due to that. Other than that, I would list some common causes of delayed / skipped cycles. Once in a while, a period could be delayed without any reason at all. Stress, tensions, weight gain, change in diet, sleep or climate, travelling, ingestion of medications which affect the hormones, late nights - all this can cause menstrual delay. Conditions such as polycystic ovarian syndrome, hypothyroidism etc can also delay your cycles. If you have irregular cycles, check for pregnancy again after a week or so. IF your cycles were always regular, then you need to consult a gynecologist if you fail to menstruate within the coming week. Please go for - Internal evaluation - per speculum and per vaginum examination Pelvic ultrasound scan Hormonal tests - FSH, LH, TSH, Prolactin, OGTT, DHEAS, Free testosterone, lipid profile, Fasting serum insulin. THe period you experienced was withdrawal bleeding in response to the pill. All the best. PLease feel free to discuss further.