What Causes Swollen Ankle Post Injury?

Hi. around 9 hours ago I was waling my dog and she was pulling game really hard. I rolled my ankle and heard a popping sound. It hurt a lot and I could bearly walk on it, but I walked it off. Itook my ugg of and it was barely swollen. Is it broken, sprained, or bruised? Please help! It still hurts and I can t walk on/move it without sharp pain.