I fell on my knee at work a few days ago and i got xrays done and everything is fine. but the swelling is getting worse and it's hard to walk. ?

Usually hurt more 2: to 3 days after the injury and that is when the swelling is the worse. Also x-rays don't show everything, only the bones. There are ligaments, tendons, and meniscus in your knee. Those do not show up on an x-ray. You may need to wait a couple days or a week and see what happens with more time. Taking a non-steriodal med like ibuprofen 3-4 times a day may help swelling. If not better recheck.