I have a severe case of thrush on my breasts and am on day 4 of 7 of diflucan (fluconazole) 200 mg and nyastatin cream and have seen no improvement yet, normal?

Fungal infection: Discuss with your doctor. May have superinfection by bacteria as well. Wash twice daily keep dry and consider washing with Hibiclens ( discuss with doc)

Absolutely no better: If you are absolutely no better at all - 0% improvement, then I would see your doctor again for a recheck and possibly a fungal culture. If you are actually improving say 25-50% but not yet normal, then talk to your doctor about extending the diflucan (fluconazole).