Could My Severe Headache In The Upper Back Right Of My Head Be Caused By Shaving My Long Hair?

Hello, I am 24, I have been getting a severe Headache exactly in the upper back right area. never had something severe like it before. It started right after shaving my head hair (I had long hair for 4 years and now I shaved it completly) It has been going for 4 days now is it just the cold? I did a covid test and it came back negative. I had aspirin it didn t help neither. Should I be concerned? Thank you