Chest muscle injury?

[ko300zx2]

I was looking in the mirror yesterday and noticed that my right chest muscle has a different shape to it.  Toward the center of my chest and on the right muscle, there is what I can only describe as a gap, or an area of what seems like missing muscle.  The area "missing" goes from right below the nipple and curves up and around  it towards the center of my chest.  When I flex that muscle fairly hard, the edge of this area seems to pulsate as if it won't hold this flex.  This just appeared yesterday or I havn't noticed until now, but normally I would notice something like this immediately.  The day before I just started working out again and did chest exercises.  I have no abnormal pain or loss of strength, only the same soreness as the rest of my chest and arms from working out.  Does anyone know what this is?  Will my chest go back to normal?!