I had unprotected sex with my GF one week before her period. she took one "plan B" pill (that contains 50 microg of ethinyl estradiol and .5 mg of Levonorgestrel) roughly 24 hours after the intercourse and another 24 hours later 12 hours third one and fourth one 24 hours after that. it's been a week now and she hasn't had her period yet, but she's experiencing lower abdominal pain and tiredness (which are said to be the symptoms of the pills) what are her chances of being pregnant?