Why Haven T I Gotten My Period After Stopping Novelon A Week Ago?

I had a miscarriage due to cervical incompetence in second trimester. and then d and c was done. Later the same month since there was a cyst they gave me novelon . I used it for 20 days and not it s been a week i stopped but still did not get my period. What should I do? I have a emergency religious travel planned with my family. And why am I not getting a period?