What Causes Pain Under The Breast On The Left Side?

Two days ago I began experiencing a pain in my left side right under my breast, Feels like someone kicked me in my ribs. I m worried that I could have a clot as about a week ago I wore compression socks and the were too tight so I cut the top of them. I work at a job where we sit all day, barely getting up for bathroom breaks and the like so by the time I realize they were not just tight from the compression, the one on the left leg caused me to have some pain right above the area of the top of the sock that has continued to bother me. I ve tried taking aspirin which subsided the pain in my side for a while but it came back and is just as uncomfortable especially when moving around. I don t have insurance at this time and I work as a contractor so I m scarred to go the hospital! PLEASE HELP ME!!!!