OVIA???

Ok so after coming across several comments of ladies stating that Glow was off on the ovulation days and recommend OVIA well I downloaded it to my phone because my CM is heavy and I'm not sure why if according to Glow I'm not on my fertile days..ok so I downloaded and signed up answered the ?s and OVIA is telling me my ovulation day was yesterday and my last fertile day is today??? So something is not right here could Glow be wrong?? On my 4th month TTC with Glow and no luck btw! Please comments!!