Glow Predictions vs OPK

According to Glow, yesterday was my last "fertile" day. But this morning I took another opk and I got a very very dark positive! Has this happened to anyone else? I also started using fertility friend on the advice of some ladies and I'm starting to believe it's a bit more accurate. Although I do love glow because of the community on here, so I'm definitely going to keep this app. So if my thinking is correct, the reason why I'm having such a hard time getting my BFP is because Ive been missing my fertile days completely! Yeah my "A-HA!" Moment. Has anyone had the same issues? I also included my last few days of opk when it tested a Yes+ any advice is much appreciated!