Help, which is correct?

B

So it's my first month temping in quite a while but we've been TTC for 17 months and I'm so anxious during the TWW. Glow says I ovulated on CD 15 but FF says I ovulated on CD 19. I feel like my FF crosshairs has my base temp really high. I know it's too early to know more, but why are these 4 days different and which is more accurate?