** Thanks for contacting with your health concern. 1. as there is the history of delayed/irregular periods, so consult a GYN/OBG doctor for a second opinion, because it could be due to certain lifestyle changes like: - excessive stress - loosing or putting too much of weight - heavy exercises - suffering from PCOD [polycystic ovarian disease] or having a high level of prolactin [hormone] 2. other common causes which can delay regular period: - stress which disrupts the ovulation: causes your body to secrete more cortisol which delays or stops ovulation altogether causing irregular periods - Also, a diet low in fiber and high in saturated fats can cause irregular periods, likewise low thyroid [hypothyroidism] can also cause the same, so check with your Doctor. 3. Another commonest cause is functional ovarian cysts which will prevent bleeding so get an abdominal USG done to exclude the same. PS. It is best to seek suggestion to know why you missing your periods, a Gynecologist [second opinion] would be ideal to consult, for appropriate examination/ investigations.