Experience with Wondfo Ovulation tests...?

Jessica • 💑2014* 👧2017* TTC 2018*
Anyone have experience with Wondfo ovulation tests? The signs say that a light second line is still negative. I'm wondering how to know there's a light positive? Also, any idea how long before ovulation they test positive? This is my first experience with ovulation tests so anything is helpful!(learn more on Glow: https://glowing.com)