Ttc and yeast infections

Been ttc for two cycles now. Both cycles right at the end of my fertile window I have gotten a yeast infection. The first month I used preseed and thought maybe that was the reason I got one. I didn't use it the second month but still ended up with one. I'm approaching my fertile window now and I wanted to try preseed again but I'm scared of getting another yeast infection. I eat yogurt and take acidophilus pills every single day and I'm not sure what else to do. Does anyone have similar issues with yeast infections that might have some insight?