I have tingling sensation on back of head that lasts 15 seconds for past few days, what could this be?

That could be tough: In that it doesn't sound like a disease process. No headaches? No new scalp products? Hair not pulled too tight? Have u been grinding your teeth at night? If this is your only sx and nothing else occurring it will likely be a transient problem in my opinion. If it worsens, evoles into headaches go in. Sometimes we can just tell whether or not something is disease, not it's exact cause. Gd luc.