How concerned should I be regarding this chest pain?

For the past three days, I have been suffering from a very unusual ailment. About three times a day, I have experienced debilitating, localized chest pain for about ten second intervals, with an occasional relapse of dull (but still highly localized) chest pain. It is below the skin, and its location (speaking from high school Biology experience, which isn't saying much) is around the left ventricle of the heart, or more likely the inner-most part of my left lung. When I say it is localized, I mean it. The point in question couldn't be larger than a dime, and is always the exact same spot. There have been no triggers. I have been both active and inactive, near and away from allergens (for me, a cat), having a full or empty stomach, etc. As I've said, it'd happened about nine times (three times a day for three days), and since it only hurts for about ten seconds, ninety seconds of pain haven't caused me too much trouble. But should I be more concerned? What could this be?