If you suspect pregnancy or have a history of having unprotected sex in the last 1 month, kindly do a pregnancy test before taking any medications for periods. If no such history is present, a natural way to bring about period bleeding is to take a decoction of black sesame seeds with jaggery twice a day. Take 2 tsps of slightly crushed sesame sedds and add 2 cups of water and boil untill 1 cup remains. strain and add a tsp of jaggery and have it before food. take untill periods start. snorting 1 pinch of black pepper powder in both nostrils once a day till periods start is also useful.