When do you consider the end or your cycle

Okay y'all, this is my second month TTC and I'm tracking my cycle and the whole shebang. I can't figure out when I should mark the end of my cycle. Do you consider having some brown discharge(very little but still noticeable) the last day of your cycle or do you not count that apart of your cycle? Do I make any sense ? So basically yesterday I had some blood obviously very light, and today it's just brown discharge. Was yesterday my last day of my cycle or was today? Thanks so much !