my last period was Septmeber 4th through the 7th, glow tells me that my period is supposed to come on Monday but I have another <a href="https://play.google.com/store/apps/details?id=com.glow.android.eve">period app</a> that tells me I am 2 days late and I was supposed to get my period on Thursday, I was gonna wait till Monday but I have seen all these polls about the calculations being off on this app. I've had safe sex this week and last week as well, but no im starting to freak out about being late! im not very good at calculating or keeping track of my period. any help or advice?