What would cause pain above my left breast every time i bend down or move my left arm a certain way?

It sounds like you -: Have, either a biceps tendonitis or a pulled pectoralis muscles. Is there a hx of an injury or repetitive activity. An xray might help to exclude any injury to the underlying bones. If its not improving, see your orthopedist. You might take some NSAID like aleve (naproxen) or Ibuprofen in the meantime to decrease your symptoms.