Glow -VS- Other Tracker Apps

Does anyone else have more than one cycle tracker app? I have two now that we are TTC #4, I've used period tracker Deluxe since 2012 to track my periods, & it's always been right on par for me.

When I downloaded Glow in 2017 to TTC #3 & input all my past cycles from my last pregnancy until the current date, Glow was 2 days off from my other app, as it is this time as well.

Was just curious if anyone else is in the same boat, last time when we TTC #3, because the trackers were off, I just extended the fertile window to include all the estimated days, & BD on like 8/10 days to ensure it would happen & it did! Might have to do the same this time.