u/swwwoggggyyyy

Hello this is my first post here and was wondering if I can get some guidance. I fell at my job in late March. Banged my knee and had a 50 lbs bag that I was carrying on my shoulder force my body into an uncomfortable position. I went to the doctor, but they did not find anything with a basic check up. I now have a swollen knee and constant discomfort in my shoulder. I suppose my question is what can I do legally as my next step. I'm in PA btw. Thank you so much.