I find it amusing that so many writers use this progress calendar thing. Goal=80K words. Progress to date 20%... it would drive me crazy just like my good read reading challenging calculator that always says I'm behind makes me slightly irritated.
I sit down to write when I feel like writing. I write for as long as it feels good. I accept the thoughts that come randomly. And I never beat myself up for writing only 100 words in a day or not writing at all. It should be, first and foremost, fun. Let yourself keep it that way.