FF wrong ?! Please help

Becka • Mommy of two precious babies 💗💙

Usually fertility friend is spot on - but this month I think it’s wrong ! I think I ovulated CD 15 or 16 - I spotted on the morning of CD 16 and my CM changed from egg white to creamy. So I’m thinking I ovulated late at night / early morning from CD 15 to 16…. Any insight? My OPK is also usually spot on - but it seems a bit off this month - really confused!