My 15 year old daughter hit foreheads with another girl very hard this morning. They both were sent home with warnings to watch for concussion . My daughter has migraines so she always gets nauseous when her head hurts, so I felt this was no different, as she is nauseous today... but also the severe headache and she is dizzy. My biggest concern is the lack of ANY swelling . I have no money, so a needless doctor visit would be very difficult, but I am growing more and more anxious, as now it has been 12 hours with no improvement. Should I be concerned? Please help.