Bump on left side below rib cage?

I have a bump on my left hand side below my rib cage. It does not cause any pain but is pretty large, at least the size of a quarter. It is also very solid. Originally, i thought it was a floating rib, but is after the angle of my rib cage. I got an ultrasound last week which yielded normal results. My blood work was also normal. Does anyone have any idea what this could be? I saw a doctor at college and have yet to see my actual physician, but my insurance is not the greatest and the appointment with x-ray would also be costly. I guess if anyone has any experience with this I would appreciate it. If it sounds bad, I will go to my PCP