What can cause right side head and neck pain?

I have been getting these head aches on the right side of my head and neck (from about my ear down ) I noticed that they seem to come pretty quickly normally after strain ( like one time I was trying to open a jar, bending over to long ). Yesterday again with no warning I got the worst headache ever on the right side and in the neck I took Excedrin Migraine like normal however it didnt work as fast and when it did it didnt take the pain completely away. I woke up today and I have the neck pain , mild head ache and My body aches (upper legs , hip area, back, upper arms,) and nausea. Could this just be the flu?