Please help clarify this..

Danielle • Artist & crafter. Vegan and devoted to being child-free for life.
I can't figure out how to log my period. Here's the issue:
​A day before I start bleeding in earnest, my CM is not the normal shade. It's either tinted pink/red or brownish. 
​Same with my last day of my period; I don't really have any flow at all but my CM is brown (I know that the blood oxidizes and that is why it's brown).
​My question is, do I include that first and last day? The days that don't have actual blood flow?
​I really want to get this right because I do NOT want to conceive so I avoid sex on my fertile days (and we use confoms, no worries).
​Help!!!