What Causes Pain From Center Of Chest To Abdomen While On Atenolol?

pain for over 24 hours, just left of center of chest...just at base of left breast..sometimes radiates down to upper left of abdomen. Off and on for days, now more constant for 24 hrs...blood pressure is normal ..I take 25 mg atenolol for high blood pressure.. 45 yr old female...overweight..not obese.