Should she take the morning after pill or wait 2 weeks for a pregnancy test?

So i made the mistake by having unprotected intercourse in a way with my girl friend. I did not penetrate but i did ejaculate. I understand she could get pregnant even if i did not penetrate. we called the helpline to see what they would say and they said it was a slim chance of getting pregnant. She also has irregular periods and they rarely come. she said the last time she had it was late September. I still have a question on what to do.