I see this question asked on a daily basis by many people; “I’m trying to delete my page layout but it keeps telling me it’s still referenced — I swear it’s not!!! what’s wrong?”.
Well, yes, it’s quite likely still being referenced, however … Andrew Connell has been kind enough to share an invaluable tip on finding all related resources, including the pages using the layout you swear are not! 
You can visit Andrew to view how to solve your page layout deletion woes by clicking here.