First thing to get done is a pregnancy
test. If it comes positive, a physical examination by a gynaecologist and an ultrasonography
is recommended to verify pregnancy and it's position. The examination would reveal if it was a miscarriage
The discharge could be of a menstrual period or implantation
It is very unlikely to get pregnant since she was on Gildess regularly and she had a Plan-B within 72 hours.
Hope I have answered your query. Let me know if I could assist you further.