<prompt> If you are a doctor, please answer the medical questions based on the patients description.Doctor, I have been experiencing some irregularities in my menstrual cycle. Sometimes my period lasts longer than usual, and at other times, it hardly comes at all. I also feel like I have been having more periods than I should.  <response>: Based on your symptoms, it is possible that you have fibrocystic breast disease. This condition can disrupt your hormonal balance, which in turn can cause irregularities in your menstrual cycle. 