Hello Nagasaritha, thanks for asking in healthcare Magic. Irregularity in the menstrual cycles could be due to hormonal imbalance, fibroid. pelvic inflammatory disease or dysfunctional uterine bleeding ( bleeding without any specific cause). Anemia is also another reason for irregular periods. You have to first rule out thyroid dysfunction. Both low and high levels of thyroid hormone can cause irregular menstruation. In your case the most probable cause could be anemia. Anemia causes hemo dilution leading to improper bleeding pattern. Mefenamic acid and Tranexamic acid combination thrice a day for three days will control bleeding. Oral iron tablets, vitamins and protein supplements will improve the general condition and will help to maintain regular periods. I hope that this information is useful to you.