Suggest Treatment For Swollen And Painful Knee

I had acl surgery about 2 months ago, have been doing physical therapy twice a week and was finnally starting to feel normal. I was messing around with some friends today and I tripped, causing my leg to bend inward. I definetely felt a crack and it hurt pretty bad for about four minutes then I was fine to walk. Im now home icing my knee and keeping it raised. It doesnt hurt just laying here but It is increadibly stiff, slightly swolen, and hurts when I try to bend or straighten it far. Should I talk to my doctor about it/is there a chance I did anything serious to it?