Left side of chest sunken in?

The left side of my chest in the area between the bottom of my pecs and the top of my rib, sinks in about a 1/2 inch, my right side sinks in a little as well, but not nearly as much. It doesn't hurt or feel sensitive or anything, and it just came there a few days ago (at least when I noticed it). I have looked it up and I saw many things about pectus excavatum, however it is not in the center of my chest and it is not as deep, so I don't know if it's that. I'm a 15 year old male if that matters. Is this anything to be worried about?