No rise in bbt but Glow indicates I already ovulated?

I am confused. I have been tracking my cycles the past two months and this past week, my cm checks were most fertile mon and Tuesday. Glow indicates I ovulated Wednesday but I have had no bbt increase? FF still have me ovulating Saturday. I know the rule 'keep having sex until you see a thermal rise' but why would Glow think I ovulated when there has been no rise. Confused!