What Causes Painful Menstruation While Trying To Conceive?

i am a doctor myself, married for 9 yrs , now i am 34 yrs old, my husband suffers from azospermia so could not have babies till now, even tried icsi , but due to abnormal sperms , that even failed. now for the past many yrs my mensis have gone very painful. and i bleed heavily. have got checkups from leading gynaecologists but every one says that its jut congestion of uterus since i have not concieved so that is why my cycle is painful. but the pain is unbearable. even the ultrasounds are normal and i ovulate normally. what should i do?