forgot intext citations

On one of the paragraphs in my 2000 word essay I completely forgot to transfer the in text citations from my essay plan into the actual essay. this was quite a small paragraph and really only needed 2 citations and I've cited in the rest of the essay but the things are basically directly paraphrased from somewhere. one of the references is still included in my bibliography because I used that source elsewhere but the other isn't and on a plagiarism check that paragraph got flagged. its already been submitted. does anyone know what type of punishment I might get and if its likely this error would mean I get zero
thanks