It could be a heart attack. It could also be a lung infection. Either way, better to be safe than sorry. Give the doctor a call, or head to the ER.
Let me find you a list of symptoms for each one:
Pericarditis:The most common symptom of pericarditis is chest pain. The pain is predominantly felt below the breastbone (sternum) and/or below the ribs on the left side of the chest and, occasionally, in the upper back or neck. Breathing causes the lungs and heart to move in the chest and rub against the irritated pericardium, worsening the pain. Pain may worsen when patients lie down and may improve when they sit up and lean forward. Changes in position can increase or decrease pressure on and irritation of the inflamed pericardium. http://www.cardiologychannel.com/pericarditis/
Heart attack:Although chest pain or pressure is the most common symptom of a heart attack, heart attack victims may experience a diversity of symptoms that include:
DEFINITION--Injury to the muscles and tendons that attach to the sternum (breastbone). Muscles, tendons and bone comprise units. The units stabilize the breastbone and ribs and allow their motion. A strain occurs at the weakest part of a unit. Strains are of 3 types:
Use instructions for R.I.C.E., the first letters of REST, ICE, COMPRESSION and ELEVATION
Hope this has helped!Kerry