Could there be something wrong with my heart?

For the past 3 days I've been having weird feelings in my chest, in the middle between my bone and on my left side where my heart is. The pain kinda comes and goes, and it's a stabbing pain. The first night I started getting the pain, I tought it was just gas so I kinda just ignored it. But when the pain continued that's when I started getting kinda worried. I got an EKG at the beginning of last year in January and they said my heart looked good. But I didn't get an EKG cause of this pain it was due to something else. Whenever I get the pain I notice I have gas afterward so maybe that's why? Could it be indegestion? what does this sound like? and I'm 21.