Confused??

Maria • Wifey//MD//dog-mommy//shoe-aholic Mommy to a toddler. TTC #2

I think Glow is messing with me. My fertile window was supposed to start 13-19th. Yesterday was my supposed to be my most fertile time..so of course baby dance. I have been testing for LH since cycle day 5 and still getting negatives, even today. I look again and my fertile window moved from the 15th-21st??!? So now I’m confused but makes sense since I have not had an LH surge. Anyone had this happen to them?? Does glow reset your fertile window based on opk?