I took fluconazole 200mg to treat a yeast infection will it still work?

Fluconazole is an antifungal. It is used to treat certain yeast and fungal infections.

The effective dose of fluconazole will depend on what type of yeast infection you have and its severity.
If, for example, you have a vaginal yeast infection the dosage you have taken should be effective - it may take several days, after taking the tablet, for you to be free of symptoms.

See: https://www.drugs.com/pro/fluconazole.html - scroll down to dosage and administration.