What Causes Severe Pain After Straining Muscle In Ribcage?

I recently strained/torn a muscle (I think) in my right side. It is painful to touch from just below my ribcage on my right side, stretching around my back. There is no visible bruising, but I am on Warfarin for Antiphospholipid Antibody Syndrome and I am quite concerned that I may have torn or even ruptured a muscle and caused an internal bleed...is this possible? I also have been diagnosed with Systemic Lupus Erythematosus and have had past incidents with slipping joints...connective tissue problems and tendon and ligament problems. I also have been diagnosed with Jaccouds Arthropathy which is extremely rare. I had a Cholesystectomy and Appendectomy, so it cannot be related to my gallbladder or appendix. I have had (ten years ago) a small bowel resection due to Ischemic Bowel (which is how they diagnosed me with Antiphospholipid Antibody Syndrome). I don t know if you needed to know all this, but I thought it might help you to diagnose my pain that has seemed to worsen over the past few days (since initial onset). Thank you.