Help never have i tested for ovulation!

Jaz👦🏼👼🏼🌈

This is the first time of me testing if im ovulating i need some help? I started sunday with my pd and ended on thursday i know shnday is day 1 and thursday day 5 but what i dont know is when to test on what day is it on day 14 15 or 10 11 12 13 can someoen give me an idea? Please