I am having sharp pains in my left upper chest behind my breast there are no triggers it makes it hard to breathe occurring more often. Any reasons?

Yes. Sharp pains can be skin, muscle, bones, stomach aorta, esophagus, pericardial, pleural etc. Mos often it ends up being musculoskeletal. Please, see your doctor.
Chest pain. Ther are several reasons for chest pains -- your heart, stomach, lungs, and/or skeletal. You should start by seeing your regular doctor who may refer you to a specialist to do testing in order to determine the cause.