My rib cage is quite asymmetrical, with one side ending in a smooth line meeting with my body, and the other side sticking up and out. (I don't even know which side would be considered "normal.") I've even noticed that some of them stick out higher up on my chest, and sometimes when I go to flatten a lump I see under my binder, I find that it's a rib. I actually asked one of my doctors about this years ago. He said "Here, feel mine! Nobody's are perfectly symmetrical." So it's totally normal. That said, there are things that can cause your chest to be caved in or sticking out, which sometimes requires surgury, but a little unevenness is nothing to worry about.