Hit her head

My 4 year old was on a small seesaw (on her own btw 😅) she ended up falling backwards and hitting her head on this plastic grey stage thing. She did have a little cry but ended up being fine and going too school.

I just got home now at 7pm and she’s randomly said it hurt when she pressed it, I felt it and there’s a small bump and slightly red. She’s her usual self as well nothing odd at all, should I still get her checked out? It only hurts when she presses it and her dad said she’s said nothing at all till I got home