Glow predictions

Ka

How accurate is glow on period predictions?!?

So I ovulated late 2/24/18.. I’ve never had to rely on glow telling me when my period might come! usually i’d get my period in the begininng of the month.. Now I’m on 15DPO, according to glow my period should be here today, but no sign of her?🤷🏻‍♀️..