You can say something like: My work is forthcoming in Pockets magazine. Or since you know the specific issue: My story "Title" is scheduled for publication in Pockets magazine in January.
After a while, when I had work published in some magazines and accepted (but not published yet) in others, I wrote something like: My poems and stories have been published (or are forthcoming) in ABC, DEF, GHI, and JKL magazines.