It sounds like what happened to me.
I was in hospital for 3 weeks with a terrible rash all over me. The 2nd week I woke up and it felt like someone was sitting on my chest. Pain but not unbearable, sort of a squeezy feeling. My symptoms turned the ward into panic stations. I remember feeling very short of breath and had to keep sitting up. Nobody knew what it was at the time, they all thought heart attack. My ticker has come through with flying colours, no abnormalities so I am now sure that it was due to ms. I did not know what it was but now I do! Now at least I know what happened. Must mention this to my Neuro. Didn't think about it while I was in his office. I hope you are feeling better. I would still consider seeking medical help if it didn't settle down. You need to be sure it is not your heart or anything associated with a life threatening situation. Take care