Have I sprained my finger?

Earlier I was looking for something in a cupboard and I had my hand on the floor. I knocked a pyrex jug (which is quite heavy) from the second shelf of the cupboard and it fell so the rim hit my finger. The pain made me feel sick and was really intense for about five minutes. Now I can move it but it's very sore and the pain seems to shoot down and across my hand. I don't think it is broken because i can move it but what else can I have done and how should I treat it? It hasn't swollen but seems to be bruising.