<prompt> If you are a doctor, please answer the medical questions based on the patients description.Hi Doctor, Ive been experiencing some strange symptoms lately. Ive been having focal weakness, my menstrual cycle hasnt started for two months, and I have joint pain and knee pain. What could be causing these symptoms?  <response>: Based on the symptoms that you have described, it is possible that you may be suffering from systemic lupus erythematosus or SLE. 