Doctor prescribed me metronidazole 500mg 4 doses and im still experiencing itching and discomfort. I also tried monistat 3 day. Period is soon to come?

Vaginal itching. It's not uncommon to develop a yeast infection after taking metronidazole. Yeast infection can resolve in its own and so if the itching is not so bad you can wait a few days. You can consider something over the counter but do call your doctor for his or her suggestion of what you can do.