my daughter fell 4.5 hours ago and hit the back of her head on a table. She has been running around and fine, no vomiting , crying (after the initial few minutes), eyes are same size, etc. She keeps saying that the back of her head hurts when she touches it. There is a red knot where she hit the table, almost like a blood blister , but bigger. She is laughing and playing and has been since a short while after she hit...should I be contacting a doctor?