Diff apps, conflicting cycles?

Kind of confused. I'm using 2 apps to track my cycles & according to Glow my period is due May 30th, which would be a 24d cycle. The other app I'm using says June 3rd, 27d which is how long my cycle is. I was tracking my bbt before I knew you had to take your temp first thing in the am. Thinking maybe it decided I ovulated early... should I go with Glow's info or just disregard it?