Did I fracture my bone below my knee?

I went swimming yesterday and I got pushed in. I hit something on the way down... But it wasn't excruitiating pain after a minute or so it didn't hurt and I could walk on it. Later on in the day it started hurting again! I can walk on it but when I bend it, it hurts but not so much where I can't take it! It's not my knee it's the bone below .... I'm icing it now and it feels a little better but when I put on the ice it feels normal but when I take the ice of it goes bak to how it was. At least it feels a lityle better than yesterday