What Causes Pain In Ribs And Petechial Rash All Over Stomach?

About two weeks ago I broke out in a petechiae rash all over my stomach, arms, legs, back; the nurse on the phone had me go into the ER and the doctor was concerned. However bloodwork(cbc & liver tests) came back fine, so they sent me home. Now it s been two weeks and the rash hasn t subsided. Should I expect this, or should it have gone away by now? Thanks! Im a 27 year old female, generally very healthy and no other problems except I ve had intermittent pain in my ribs over the last year or so(kept thinking I was just sleeping wrong until the nurse just told me otherwise). I have an appointment for the pain and to follow up with the petechaie this Friday. My curiousity is just getting the best of me! Thanks for your help!