It's not too late, as in as long as your school deadlines aren't Nov 1 then your application will still be valid. But the later you submit, the further down the line you go for rolling admissions. Plus, you won't get supplementals until your stuff is verified, which could take weeks.
However, I submitted my application on 10/13 and was verified 6 days later. But the closer to deadlines we get, the longer verification will probably take as the applications pile up.