How Should Persistent Vaginal Thrush With Blood Pressure Be Treated?

hi Im 40 year old and have been on Noriday 28 day contraceptive pill for over 4 years now. Im also on Bendrofluazide for my blood pressure. Just lately for the last 3 months, I have been getting thrush, either before or after my period. I have been using Canestant 6-day to treat it, and it will go away for a week then I start to feel that its coming back ;(. Do I need to see my GP to change my pills or is there something seriously wrong with me?