Lower Abdominal Cramping, Nausea, Frequent Urination And Fatigue. Reasons?

Hello my gf took a plan b pill October 9 3 hours after sex, she felt a little nausea after and the next day then it went away, she was expecting her period October 15 but got it on the 16 a day late, it was a heavy period for about 3 days the next day i was pertected wirh a condom and had intercourse later that day she had spotting Very light pinkish it was the last time she had spotting and Very first. Last Thursday she had lower abdominal cramping and nausea pretty bad felt tired, peed alot and felt sick too today she felt better but im concered what this might be ?