What Causes Breast Tenderness And Pressure In Abdomen After Periods?

The last 3 months I have noticed some changes in my menstrual cycle. The week after my period I have breast tenderness, mild cramping and pressure in my abdomen. I am super moody and hungry all the time as well. Also my periods are changing, they are not as long or heavy. It s like I have all these signs of being PG but negative tests. I have a doc appt next week but I was just wondering if u had any suggestions as I am going crazy wondering what s wrong with me?!? I had a abnormal pap last year, but it turned out to be nothing. Could something serious still be wrong?