FF moved me from CD9 to CD12 and now huge dip

Hi all, I was expecting my period Sunday feb 17 and I am pretty normal 22 day cycle/ 14 luteal phase. FF says my O was CD 12 that would put me on 12pdo. If my O was late does that mean changes my luteal phase that’s why my period is late? I did have a huge drop today below coverline. Thoughts