Extended Stomach and pain

My stomach has been painful for 2-3 months.  It is now extended in the last 2 weeks.  I had an ultrasound and blood work done- they said it was negative.  There appears to be nothing wrong with me according to the doctor but I still have cramping pain, bloating and my stomach is hard as a rock.  I have no uterus as I had a hysterectomy a year ago.  I do have one ovary on the left side.  Any suggestions as where to go from here?  My primary sent me to the OB-GYn and she sent me back to my primary-