Green’s Dictionary of Slang

pregnant; also in fig. use.

1938		N. Marsh Death in White Tie 63: There was your bag, simply preggy with banknotes, lying on the writing-table .
1961		S. Price Just for Record 57: If poor little preggy Emily Nugent had lived I might never be where I am today [OED].
1969		A.S.C. Ross What are U? 14: ‘She’s pregnant’ is now used in many classes (‘preg, preggy, preggers’, whatever class they belonged to, are now not much used).
1970		H.E. Bates A Little of What You Fancy (1985) 581: How did they work it? Drop a tablet in and if it fizzed a girl was preggy. If it didn’t she wasn’t.
c.1973		J. Thompson ‘Sunrise at Midnight’ in Fireworks (1988) 180: That chick who got herself preggy in one of those jumping-juniors joints.
1989		H. Rawson Dict. of Invective (1991) 309: Mothers-to-be generally were described on formal occasions as [...] preggers (or preg, preggo and preggy).
1991		B. Hamper Rivethead (1992) 22: There was no way in hell they were gonna allow her to waltz the hallways in her preggy state.