Dudes, it's weird.. Does anyone else's sternum "crackle" when you do certain motions?

Sometimes, usually in the morning, if I flex my chest really hard with my arms crossed over my chest, then hold the flex while I bring my arms out to the sides for a hard double bicep pose, my sternum will make all sorts of snapping and cracking noises. Is this normal? It never hurts at all, I'm just worried about future problems that might arise in my sternal tendons or something..