Hi, Menstrual cycles with a length of 21 to 35 days can be considered as normal only. If your cycles are consistently longer than this, you may need to get evaluated. By clinical examination and by investigations like ultrasound, hemoglobin, blood sugar levels, thyroid profile and serum prolactin level estimation, the possible cause of your problem can be identified and treatment can be taken accordingly. General measures like taking healthy, balanced diet, regular calorie burning exercise and maintaining the normal body mass index also help in regularizing the menstrual cycles. Menstrual irregularity may not always lead to infertility by correcting the cause of the problem with proper treatment chances of pregnancy can be improved. Take care. Hope I have answered your question. Let me know if I can assist you further. Regards, Dr. Sree Gouri S. R., OBGYN