Hello,
Welcome to ehealthforum and thanks for writing
I pill is an emergecny contraceptive pill and is quite effective in pregnancy prevention if taken within 72 hours of the intercourse.It contains high doses of hormones which can cause side effects as withdrawl bleeding,abdominal cramps,bloating,nausea,vomitting etc.It seems that the bleeding might be due to the pill intake.
Regarding the pregnancy though it is highly effective in prevention but 1 to 2% of failure chances are also associated.Right now just ask her to relax and take adequate rest.The next periods might also be delayed by a week or so.If they do not start even after a week of the expected date then consider doing a Urine test for pregnancy determination.Kindly visit a Gynaecologist for evaluation.
Take care!