Strange feeling in my chest?!

The past couple days I have had this funny feeling in my chest, right in the middle. It does not hurt but it is a strange sensation and when it first started I thought I was getting a cold or something. However, I started to feel the sensation in my bottom jaw, like in the front row of my teeth on the lower jaw, if that makes sense. I do not have a family history of heart problems that I know of. The sensation comes and goes and SOMETIMES I feel it a lot more when I lay down. My breathing seems fine, but when I inhale I feel it. No pain any where else. Does anyone know what this might be? Or what might be the cause? Thank you for your answers!