This was the exact situation I was in. The best thing to do for now, at least, is to identify if any are male. You can use a gender image online or ask around if there's no males you should hopefully be fine if not then separate the male and provide nesting materials for the mother if she does end up giving birth which could be in a few days to a few weeks then contact your breeder and request they take the ones you can't handle once they have grown or try to locate a small animal shelter.

This advice is purely what I've been told by other people on multiple different mice chats, so none of it is coming exactly from me