Sudden change in fertile window, help plese

Yadi • Married since May/2011, Now mother of a beautiful baby boy!
At the beginning of this cycle Glow Indicated my fertile window ended on saturday Jan/18. I started to log my bbt at the beginning of the fertile window just to see the trend (i am not ttc right now). The first increase in temp was around Jan/15 (CD12). My cycles are usually 28 day cycles. This morning I noticed the program changed my fertility window, now ending today, meaning my highest % was on Monday (CD17) and is also saying my next period will be on Feb/4 (CD32). Does this make sense? I am really confused now. Help please.​