my doc office got someone's files mixed in with mine.the infusion caused an allergic reaction.how do i find out if they gave me the wrong thing?

the doc asked me if i was on a blood thinner. i asked the nurse if something was too low or too high and why he thought of a blood thinner. she told me someone elses file had been put into my folder an she was going to request it be taken out. i had an allergic reaction that night but didn't realize it. i was not feeling any better the next day, went to the e.r. i think when the doc gave the ok for the infusion they gave me something i wasn't supposed to get. i have already had 7 or 8 of these infusions. if i was going to have any reaction, it would have already happened. the 3rd doc i saw at the hospital said i prob had a spine problem. i was swelling around my hands and face, it felt like i had an elephant sitting on my chest and it was very hard to breathe and my left arm was going numb. the er said it wasn't my heart, so i wondered if there was a mix up in fluids with another patient