Ovulation test vs glow app

My ovulation tests are faint which means, I’m not ovulation/ I don’t have an LH surge... it’s suppose to tell me when the surge will happen within 24-48 hours and my <a href="https://play.google.com/store/apps/details?id=com.glow.android">glow app</a> says I should be ovulating in 2 days. I don’t know which to believe! If I I’m suppose to ovulate in 2 days then I should have my surge now right? But the ovulation tests say I don’t!