Has anyone used the Glow app or something similar?

[nicem815]

I have been using the Glow app for tracking ovulation and periods. My last two periods came on the exact same day (the 22). So, originally my period was predicted to be on the 22 with my fertile window at the appropriate time preceding that. I took some ovulation tests and I was showing LH surges on the 18 and 19. When I entered that information, it pushed my expected period date back to the 27. It did that for me last month as well, but my period came on the 22. Basically, I have no idea how accurate it is and if I can even rely on it to tell me my fertile days because it's been wrong. Anyone have any experience?