Depends on the cause, some yield is already lost but an extra week or so might help recover some of it. Mainly you should harvest by trichome color, don't let it go so long you lose the up buzz (unless you want a couchlock).

I had a pH problem which caused some nutrient lockout, it's stabilized now and after 3 days I see new pistils at the top of my buds. So, watch and wait.

Good luck.