TTC for 6 months. The last 3 I've had irregular periods. I just stared using opk this month. As you know glow shows your estimated most fertile days. The past week, every time I enter the no lh surge on my calendar glow recalculated my fertility window. This morning I got another neg opk, but when I entered it my calendar didn't change. I am just wondering if anyone else has had this issue on glow. Also those with irregular periods, how does your ovulation change month to month. This is totally new territory for me. Thanks!