Why am I suddenly getting headaches?

Greetings,

Ive been RAW for one month now. Ive only been consuming fruits, veggies, grinded seeds and nuts in the form of dressings and nut butters. Due to my slow digestion I find its easier for me to not eat nuts and seeds without breaking them down and not eating them straight out of the bag. I have not gotten into sprouting lentils, etc... as of yet. (I want to give a bit of history of my diet. Question: I have woken up with a headache for the past 2 mornings.  I havent been able to immediately check my blood pressure. Any suggestions as to why Im suddenly gettinfgheadaches? Ive been fine up until now.

Thank you kindly!