I had a heavy light fall on my head last week. there were no concussion symptoms for a week, but today i woke with vertigo. is it likely related?

Possibly: Your head trauma may have caused an inner ear concussive force, dislodging otoliths, which could now be stimulating the hair cells aberrantly, creating a postural vertigo. Alternatively, if there is also nausea and/or vomiting, this could represent a sporadic viral labyrinthtitis. If this persists or progresses, contact your doctor. Lots of therapeutic interventions.