The back right side of my head has been tender to the touch for the past week. i have not hit it?

Have someone check the back of your scalp to see there's any sign of inflammation or lesions. If no scalp pathology, you may be dealing with irritable or mildly inflamed superficial scalp nerves or which usually resolve on their own. However if it's impending shingles infection a breakout of scalp lesions would occur by the next couple.of days. See your MD as needed.