My ovulation date changed? Should I be worried im pregnant?!?

Keisha

I been following <a href="https://play.google.com/store/apps/details?id=com.glow.android">Glow app</a> for 6 months. I recently tested for ovulation and it came back positive. But my <a href="https://play.google.com/store/apps/details?id=com.glow.android">glow app</a> said I should of ovulated 3 days prior. Help!!!!