Suggest Medication To Prepone Periods

my periods date is on 16th of nov but iam scared if it happens on 19th as im having program to visit kamakhya temple and my tickets are on 19th nov..so if u can suggest any medicine to prepone it because i dont want to postpon because its the out station visit for 10 days and i dont want of tension dat tym.my last periods was on 16th oct..pls suggest im running out of time n need to prepone it immediately by tomoro..pls help