Weird breast/chest feeling..

So, I thought I was having heart palpitations because whenever I breathe out it feels like my chest/breast are quivering or kind of feel tickly (how vague, right? But it's the best way I can describe it)!

I went to the ER because it's nearly constant, I got an EKG and blood work. EKG was perfect, BP was fantastic, and all blood work came back awesome! Dr said it's definitely not palpitations, but he doesn't know what it is, but it's not life threatening.

Do any of you have any idea what could be going on? I'm 18 weeks pregnant and I suffer from pretty severe anxiety. Could this just be my nerves and anxiety causing havoc because of my hormones? Any and all helpful input would be appreciated! Thanks ladies!!