Suggest Treatment For Missed Periods,tender Breasts And Abdominal Distension

hi...i have a mirena for over a year now and since that my period stops, my stomach looks like 3 mos. pregnant, it sucks coz everybody is askin me if i am,but im not! i felt really dizzy sometimes and my breast is very tender..its crazy!!!i took a pregnancy test a month ago and it came back negative..pls help!