What Causes Severe Abdominal Pain During Menstruation?

Hi this is Mary my daughter Bianca has extremely bad periods, she is 24 years old . Her period is approaching very soon. Her stomach is huge more so then usual as she has put in a tx msg to me today. She is at work right now. I do not know what to do for her, I do not want her to go through this much pain . I can not afford to pay for an answer , I will call my doctor now. thank YOU