Can a bad yeast infection delay a period? I’m 99.9% sure I’m not pregnant, so that’s not a concern I have. I have a really bad yeast infection though, that I’m taking medication for. I was supposed to start but I haven’t. So can a yeast infection delay a period? I’m not super worried but to a point I’d prefer to have this calm down before my period hits because my periods can be utter h*ll.