Green’s Dictionary of Slang

(US) pregnant.

1955		W. Gaddis Recognitions I 172: She’s preg, baby.
1960		G. Swarthout Where the Boys Are 235: Incidently I was preg. That’s right, p.r.e.g. I’d been sure for five days.
1985		O. Hawkins Chili 91: I was going to tell her I loved her, the minute i found her ‘unpregged’.
1992		D. Burke Street Talk 2 28: She looks preg to me.
2012		M. Lacher On the Bro’d 109: He totally got Carly pregged up and had a fucking little girl [ibid.] 246: ‘He wants to know what’s up with all these chicks I got pregs’.