Glow or Ovia

Haley

I try to use both apps to predict most fertile days! However they never seem to match up. Glow says today is my most fertile day. Ovia says it was yesterday. Which have you all found to be most accurate? I got my first surge OPK this afternoon. Last month I got one late afternoon one day, and then until like lunch the following day, I was still "surging." I'm just curious as to if yesterday or today is my most fertile day.