Community medical question

Hello. So my wife has taken this Emergency contraceptive (Geeenstar ECP which is basically 1.5 mg of Levonorgestrel) 24 hours after sexual contact. The first 6 days went by with no problems but at day 7 after taking the pill she started experiencing bleeding which keeps on increasing day by day. Its the 4th day now and 11th after the pill. The bleeding is accompanied by back pain. What should we do? Should we be worried?