What Are The Side Effects Of Regestrone Tablet?

hi...doctor..please give me the information about regestrone tablet. actually my marriage is jun12th.every month i have regular periods on exact date next month. last month my date is may 10th according to that it will happens jun 10th.this may be problem for marrige.thats way when i consult my doctor she suggested anin injection for preponed of my period date.i took the anin-250 injection on may 26th.my doctor give the period date for june 6th. if the period date not happend she told me that to take the regestrone tablet every night for 10 days .is it safe or not? or is there any problems are raised after using this tablet. because I m very scared to use tablet.my friend said that if we take that tablet for 15 days it will create major problems while pregnancy... and will effect the child health also...pls..help me. doctor...