20 years back, I had ankle injury. Is it worth investigating now?

Hi doctor,

I have a question about my ankle. When I was at school, I was messing around in the changing rooms one day after PE. When I went over on my ankle, I heard a loud crack and experienced instant severe pain in my ankle. When I tried to limp into the nurse's room, I passed out in the corridor. I could just walk, but it was incredibly painful and I could put no weight on my ankle. My mother collected me from school and took me to my GP to have it looked at. My ankle was swollen, really badly on the outside (a lump) and on the instep was a long black bruise. My GP said it was just a sprain and sent me home with a support bandage. I remember it being a good while before I could really walk again. Fast forward 20 years and I still get pain in my ankle if I step the wrong way and it feels weak. I recently had to walk through an uneven field and it bothered my ankle a lot. It bothered me again last night. So, I was wondering if it was likely more than a sprain when I did it. The crack was really loud and I was quite annoyed my GP did not even suggest an X-ray. Is it worth investigating now? It was 20 years ago and it does not cause me a great deal of suffering.