Hello and Welcome to ‘Ask A Doctor’ service. I have reviewed your query and here is my advice. Usually after establishing of the menstrual flow progesterone tablet may not help in stopping it with regular dose. But if you take it in higher dose like twice a day or thrice a day that may help in decreasing the menstrual flow but taking higher doses can lead to complications like nausea, vomiting, irregular menstrual cycles etc. So, better to avoid. Generally if you want to postpone the periods you have to start the progesterone tablets at least 4 to 5 days before the expected date of periods. Hope I have answered your query. Let me know if I can assist you further.