What Causes Stomach Ache And Pain Behind Breasts While On Birth Control Pills?

I have a stomach that has been persistent for 24 hours. I have aches, am tired and a fever of 100. I am 43, very physically fit. I just started getting a stabbing feeling behind my right breast, through my back. I have been in bed all day. I am on birth control pills. Am I having a heart attack or a pulmonary embolism?