Severe pain under right rib cage/liver area

Hi, Ive been suffering with pain on the right side of my ribs for about 3 weeks now. The pain feels like its underneath the front of my rib cage and sometimes on the back. There is constant dull heavy pain that covers the top right section and into the middle of my chest, but the worst is the stabbing pains. They seem more localised and pretty much always in the same place. I went to the Dr's 2 days after i noticed it, he said it seems that Ive caused severe trauma to my ribs and sent me away with ibuprofen and was told it will be pretty much better in a week. I thought it was slowly getting better but even with the painkillers it still really hurt. But Saturday somebody barely knocked into my side and it was agony, even worse that the first time. I was sick and completely dazed and out of it for the rest of the day. I went to a walk in Dr and he said it might be a pulled muscle and sent me away with more pain killers. I know i'm not a Dr but I've pulled/torn muscles before and it doesn't feel the same. I can be sitting doing nothing then suddenly be in agony. From what i know i haven't done anything to cause trauma to my ribs or pull a muscle. But i'm still sitting here in agony. Does anyone have any idea what it could be?