Using Glow to NOT get pregnant?

I got back into using Glow to track my cycle. Before, I would use it to predict my period, but now that I'm sexually active I use it to track my cycle, my BBT, and cervical mucus because I was too afraid of the negative effects of hormonal BC.

Anyway the point of this post is to see if anyone has used Glow to NOT get pregnant? Especially when adding daily BBT and CM, has it been accurate?

And for the ladies who have irregular periods often, does Glow adjust to reflect that?