Glow or Ovia?

Ariana • After TTC #1 since August 2015... Preggo, due date April/17 !!!!!... (MC July 2014 (12w), Oct 2015 (5w), Dec 2015 (6w))
Why my fertile phase is so off between Glow and Ovia?  Does it happen Toyota guys also??
Well, we tried last month with Glow days, and didn't work out!
This month I decided to follow both... Hubby is pretty happy tough... Hehe