What Causes Delay In Periods After Stopping Ecosprin Medication?

Myself poonam.. I had a failed ivf cycle once.. N im called for frozen embro transfer last month.. I am taking Emgra 2mg three tabs n Ecosprin one daily nite..i have started taking this tab from 3day of my last cycle,that is 28th dec.. N i have been taking this tabs till Jan 26th...with periodic sonography as well..now doc has told me to stop my tabs n meet once i have my periods.. But even after stopping my tabs on 26th i havent got my periods.. Can u tellme how this process goes? I am worried as doc has not explained me the procedure too.. R my periods postponed due to emgra tab? How many more days i wont have my periods?