Natural ways to whiten teeth while pregnant?

Hello! I am struggling a bit from yellowing and want to brighten up my smile at 27 weeks pregnant. I do drink one cup of coffee daily, so ultimately I do know this contributes to most of my problem.... but I simply cannot live without my one cup a day. I brush religiously morning and night and floss. I know that whitening strips are off limits and a lot of “safe” or “natural” products actually do significant damage to enamel. Anyone have any fabulous tips or tricks for some pearly whites? Thanks!