How long for Diflucan to work?

The last time I used Diflucan eas YEARS ago, so I don't remember. I started having symptoms of a yeast infection last Sunday. Monday I called my dr for a prescription because OTC is horrible. So Tuesday I got my prescription and took it, itching started going away Wednesday. Took second pill Friday as prescribed. Itching is gone, but my left labia is slightly red and irritated still. Any thoughts? Is it going away pr should I call my doctor again? I'm wondering if I'm just irritated from the infection and the medicine. I'm in my 40s now so I know things are going to start changing in how the work.