The left side of my chest has an uncomfortable bump.

So, I noticed about a week ago that I have lump or bump on kind of the middle of my body (right where the bottom of my ribcage is). It's a little uncomfortable and a little painful and the pain kind of irradiates to my left shoulder blade but I can still go about my day, it's not unbearable. Now, just today I was working and the lump kinda popped really quickly and then it got smaller. So, I guess I'm wondering if anyone has had something similar and knows what it could be.

It could be your sternum which is right in the middle of your chest just below the ribcage. People often discover it as a lump, and panic, thinking its a tumour of some sort.You may have a small injury to the area caused by muscle strain and the popping is the muscle going into spasm.If this gets worse do see your doctor. You may have a small local infection in the sternum which may need antibiotics