Hello, I Have This Pulsating Feeling On My Upper Left

Hello, I have this pulsating feeling on my upper left area of my chest (is directly across from my arm. Basically below my armpit. And it vibrates every so often and just recently it has increased and also expanded to my arm. I can feel the pressure and it just sort of blows in and out as if it were a hernia sort speak. I never felt this before until a couple of weeks ago. I'm wondering if this is something serious I should have checked. Thank you for your time.
Armando