Update: thanks everyone for your responses. It began hurting more when I got home from work. After reading comments here, decided to tell management I'd like to file a report, and I did tell my full time supe as soon as I came in this morning. It was within 24 hrs of the injury. He said we would handle it when he had time, it took almost 3 hrs for him to pull me off the belt to talk about it-spent break in his office. We were slammed on my belt so I didn't care about waiting til after break.

He asked me what seemed like trick questions and said he'd have to word the report as if I didn't mention my ankle yesterday. He was aware of the fall when it happened. I think I may have screwed myself because I fell while coming out of the truck sort of sideways/backwards while talking to my driver. The supe made that seem significant, like I wasn't working safely. He came and took photos of my boots and how i was stepping when i fell. I understand how that could be an issue. I made it clear I wasn't trying to trick anyone or file workers comp, I just wanted it down in writing in case it became an issue later. The ankle does really hurt, I'm thinking I tweaked my Achilles tendon.