For past 3/4 weeks i keep having a pain that comes and goes in the front of my shoulder at top. scared it's something serious or dangerous ?

Shoulder: The common cause of such shoulder discomfort in your age bracket, excluding injury or sprain, would be tendonitis. This is usually diagnosed by finding a tender spot and noticing increased discomfort on shoulder motions. It responds to cold or hot applications and taking anti-inflammatory medications like Advil or Aleve (naproxen). For further evaluation see your physician or an orthopedic specialist..