How To Treat Abdominal Pain In Periods?

Hi Im 46yrs old and I have been having pain on one side of my lower abdomen that feels like labor pains it seems to get worst during my menstrual cycles. Last month I was in severe pain and was going to go to the ER but as soon I was about to leave I felt something burst on that side and the pain went away. But now the pain is back again.Any suggestions on what it could be or what I should do?