Different Ovulation Days?

Looney

Hey guys, so I have just downloaded this app because my friend swears to me it’s the best so I did. However before I was using Flo as a tracker. My problem is that Glo tells me my ovulation was Saturday 9th and Flo said it was on Friday the 8th.

I had unprotected sex twice yesterday thinking my ovulation passed.

What do you girls think? Which day is accurate? My periods are regular by the way