Yeast infection from antibiotics

Hey. So I'm on antibiotics for my kidneys. I've been taking them but I think I may have developed a yeast infection because it just feel uncomfortable downstairs. So I went and got a monistat 1 day treatment. I never tried the one day before. I've always gotten the 3 day but Walmart didn't have nothing. So I took it last night, the 1 day treatment. How long does it take to kick in and finally be good?