There is no use taking emergency pills after 7 days.
This is because like other pill Nordette
is also effective in preventing pregnancy
only when taken within 3 days of unprotected intercourse
Since you have used withdrawal method the chance of conceiving are less.
Besides taking emergency pill now would not give you any advantage rather side effects like delayed period or unexpected vaginal bleeding can occur.
You can take up a pregnancy test if you miss your periods and consult a gynecologist accordingly.