C.P.
I mooshed my pinky in a car door when I was 8. The nail bruised and eventually fell off. It grew back. Today you can't even tell it ever happened.
Fast forward to two weeks ago. My 10 year old mooshed HIS finger in the car door, but only part of it. So the nail bed is still connected. But it looks gross.
His nail likely won't fall off, but once the nail bed heals, it will grow normally again. This can take a while.
So don't worry. Just keep it clean and eventually it will start to look normal again.