What is wrong with me? did i have a heart attack or somthing?

first off i'll give some info that might help you answer, im 15, male, 5' 7 ", im in shape, im about 145-155 pounds, and i dont smoke, drink, or do any drugs. ok so my left side of my rib cage sticks out right under the chest area a bit at the top so there's a lump, its been like that since i can remember is that normal?, and just recently i,ve started having chest pains, whenever i inhale it hurts, i looked at a picture of the human body and where it hurts when i inhale is like between the pectoralis major and the deltoid, and somtimes it seems like the pain changes places around that area, and once when i inhaled i pushed my shoulders forward and my pectoralis major, the part thats part of your arm pit like strained or something and was in pain for like 30 seconds, i thought i was having a heart attack or somthing at the time, so wtf is going on here?