Thanks for your query.
White dots and patches on the throat are commonly seen after ingestion of Metronidazole
Most probably the reason for your symptoms is the antibiotic prescribed.
However, you have not mentioned why the metronidazole was prescribed to you.
It would be only given for a few days, and mostly the symptoms would disappear after the drug is discontinued after the prescribed days of medication.
Please consult your gynecologist , as the symptoms appear to be quite mild, and also , stopping antibiotics abruptly and suddenly is not advised.
ALso, other rare causes of such dots or rashes should be ruled out.
Take care, and feel free to ask further questions.