Hello! Thank you for the query. When period appears, women are not fertile. Neither are two days before period. Most possible pregnancy is in the middle of the cycle (which is about 14 days after period start). She may be pregnant anyways. You need to verify it with pregnancy test. However most probable reason of her symptoms is reaction to the hormones taken (Morning after pill contains large dosage of hormones). It is also possible that cramping and nausea are not related to the intercourse, pregnancy or taken medicine. She may have an infection (diarrhea would appear). If she does not excrete gas and/or stool, bowels obstruction should be also considered. I suggest her to visit a doctor as its too much possibilities. Physical examination should be done and depending of the suspected reason proper diagnostics. Hope this will help. Regards.