What Causes Stiffness, Swelling And Pain In Forefinger Joint Post Injury?

I hit something hard and now my forefinger's middle knuckle is slightly swollen which i didn't notice right away, and there is a faint bruise on the lines on the palm side of the knuckle, it hurts to bend all the way and it's stiff. Do you think it's broken? The swelling and bruising are barely noticeable which is why I'm unsure, that and I've never had a diagnosed break.