Protruding Sternum

I slept early yesterday, woke up once due to sensitivity to noise. There were no signs of any K type activity that I was aware of. When I woke up this morning I was glad I got 8 hours of sleep, but I still felt tired with a heavy weight feeling. There was a strange sensation near my chest. Something felt different. I checked exactly where the sensation was and discovered that my sternum was protruding (the middle lower part of the chest) - not too much to look scary but enough to scare me. Even the bones in my back and spine feel different. There's also a slight indentation just below sternum, like it's sucked in. Fortunately it's not painful.