@Junethe black dot is the New Moon, the red flag is when you are most fertile, the yellow dot is the Full Moon.
like i said in the August example:
the first yellow dot is Full Moon on Aug 2nd
the black dot is New Moon on August 17th
the red flag is August 19th/20th(depends on your time zone) lol
the second yellow dot is Full Moon on Aug 31st
so the red flags are when you should be most fertile.
i don't know how menstruation+ovulation fit in though(like it says on bottom). i hope someone with actual experience pitches in on this. lol
and i have no idea why there is no gender in August? maybe having 2 full Moons in August is too much? lol no clue.
i don't know if this works for men. i assume it's designed for women only.