Its very unlikely you would pierce your heart, but piercing the lung is a different matter.
anyway, in this case i would say it is simple bruising. I say 'simple' anyone that has had a bruise (ie everyone) will know it hurts to touch it - which is pretty much what is happeneing everytime you breath in.
that you tell us in the 1st line "aching pain" lets us know this is really nothing to get in a flap over.
Simple advice - Take some aspirin or ibuprofen (paracetemol not so good for this kind of pain) to relieve the pain somewhat. If you find yourself getting short of breath, dizzy, racing heart etc then by all means go to the docs/hospital. But this is an utter worst case scenario and 99.99% of people in your situation will be utterly fine.