Both shoulder blades hurt sharply and it also hurts when i take a big inhale. it's been 2 days. i do have high blood pressure. just began working out?

Probably a muscle: strain, but pain in your upper back/chest is a bit of an unusual location. Also, pain with inhalation is of concern. I don't have your age, or whether or not you are a smoker or might have asthma. I would get this checked out, mostly because of the VERY unlikely possibility this is pulmonary embolism, or blood clot to the lung. Go to ER/Urgent Care or your doctor's office today! Best wishes!