Sentence:  Or you could hope the parachute would n't open just so you could say you saw it not open , not because you meant any harm to Starkey Poe in his suit of red underwear , but mainly because you were tired of being an old maid - a thing which cannot admit when it thinks it might be pregnant , but must stand the dizzy feeling all alone and go on like everything is all right instead of being able to say to somebody in a normal voice : `` I think I <WSD>'m</WSD> pregnant '' . 
Meaning of the word marked with <WSD> tags:  have the quality of being; (copula, used with an adjective or a predicate noun)