More on Negative Pregnant from Infoplease:

• Negative Pregnant - Negative Pregnant (A). A denial which implies an affirmative, and is so interpreted. A law term. ...
• Federalist No. 32 - To the People of the State of New York:
• Dictionary of Phrase and Fable: N - Definitions, origins, and illustrative excerpts for words, phases, and literary allusions starting with "N"