I would consider anything new or changed, like, body soap, laundry detergent, fabric softener, even new undies, if you're sexually active new condoms, spermicide, partners new soap, laundry detergent etc. Maybe it's an allergic reaction.
There's also the fact that i'm not sure that a yeast infection has to have discharge or odour, it still might be a yeast infection, maybe really low grade. If it was me i'd go to the doctor, or I might just try an over the counter medication for yeast infection and see if that helps.