Thanks for the query.
tablets are prescribed for 3 or maximum of 5 days.
One course of tablets with daily 500mg to 1000mg for 3 days are usually sufficient after cervical cerclage
For more details:http://www.medicinenet.com/azithromycin/article.htm
So you better once again verify about the prescription with your doctor.
If she again says the same better to go for second opinion
from another local doctor.