What Causes Delay In Periods Inspite Of Taking Mifepristone And Misoprostol?

Hello sir,My girlfriend had her period in the month of January 2015 on 25th and den we had protected sex for one time and there is no period on the month of february so in the month of march on 12th I had given her mifepristone and misoprostol but nothing happens except white discharge and yesterday she had very light period and it stops now no blood and no white discharge please help.