My son, 20 months, fell and hit the back if his head at the pediatrician yesterday. Cried, then seemed ok. Ped said use ice. This morning, he woke with a fever. Was cranky and tired all day. Went to bed at 6:00. Now, he just vomitted then went back to sleep. Should I wake him & go to ER now or wait until tomorrow and go to his pediatrician?