What Causes A Throbbing Pain In The Right Side Of The Head?

Hi i have on and off throbbing and slight pain in vein right hand side of head[lasts about 10 seconds between 1 to 10 minutes apart Im 70 years old 6ft tall 84 kilo and use exercise bike--lift weights--swim every other day as sometimes when i push weights my joints crack so i recently started taking 1 fish oil pill a day could this be the cause thanks