@Ana1234 - Yeah, I have a few sporty friends and it seems like it's happened a few times with them. I had one who was in the territorial army and had injured her leg, but thought it was a sprain. They had some kind of last exercise they needed to do and she just kept on going, even though she was limping really badly.
Everyone was really impressed when it turned out that she had done it with a fractured ankle, but the medic told her that it was really stupid. It's easy to brush off something when you know you can keep going, but you can end up doing more permanent damage, so it's a bad idea.