Accuracy with this App

Tiffany • I am 25 years old, I have one 5 year old son, and a wonderful husband. I got my mirena removed 03/25/16 after 5 years of having it, and we are currently trying to conceive :) yay!!!!!
I was curious to see how accurate this App has been for you ladies. I have glow and Ovia fertility, and I put in the same information for each but they give me completely different days for fertility and when my period is supposed to start. It's frustrating when one says I'm fertile and the other says I'm supposed to start.