Glow predicted my period was due the 30th october and it actually came today the 26th october. This is my 3rd month TTC using Gliw and introducing all yhe data, and I have never had such a long cycle as the one initially predicted by Glow for this cycle -33 days, when my average is 30 days. I am not happy with Glow's inaccuracy. I think other apps are much better. Worse thing is I don't trust its predictions of fertility period, either.