What does it mean when i take a deep breathe and i feel a sharp pain in my chest, could i be having a heart attack. please im scared?

Not likely: Hi. Take a deep breath (pun intended!). Unless you have a dreadful genetic disease with a family history of profoundly premature heart attacks, this isn't a heart attack. And heart attack pain is (almost) NEVER described as a "sharp" chest pain. You should see your doc to see if pneumothorax, pleuritis, costochondritis, etc, could be responsible. Good luck!

Unlikely: Typically at your age this symptom would not indicate a heart attack however it could indicate a serious problem like pneumonia or a blood clot in the lung if you have other symptoms like cough, fever and sweating in the former or shortness of breath in the latter. More than likely, this is neither of those and unless you have other symptoms, I would suggest you make an appointment with your doc