I think I may have broken a rib?

On Friday, while I was playing cricket, I had a bit of a collision with one of my team mates, he kneed me in the ribs by accident. On Friday night and all of saturday I had a bit of discomfort which I thought was just bruising, however since sunday afternoon it has been steadily getting worse, I have pain when I take deep breaths and when I laugh, getting in and out of bed is a bit uncomfortable too. Anyone have any idea if I may have broken a rib? Im on ibuprofen at the moment and it seems to have taken a bit of the pain away.