I Have A Yeast Infection, I Went To Shoppers Today

I have a yeast infection, i went to shoppers today where the pharmacist told me canesten would work to clear the symptoms, i am also breast feeding my 3 month old daughter. I asked her if it was okay to take canesten cream while breast feeding she said yes its fine, so i went home ans inserted the cream, now im reading online that i should not breast feed? The box also says no breast feeding? Just woundering if it is okay to breast feed? And how long does it stay in my system for?