How do these work?

Truly Blessed • 👼🏼July 2017 👼🏼 June 2018 . Rainbow 🌈 baby born 2/17/20

So I gotten tired of spending money on the clear blue advance ovulation test . So I'm switching to this kind

So, I want to make sure I'm using this one right. When both lines are both dark that means I'm ovulating Right????