Did she get her period? Pulling out does not prevent pregnancy. The penis emits a small bit of sperm during intercourse and it's 'enough' to impregnate someone. But that doesn't mean she's pregnant. Women/girls can be late at any time for many reasons which include changes in routine and schedule, stress, weight gain or loss, illness, or just a hormonal shift. They then are late. She can take a pregnancy test 2.5 weeks after the episode of sex you're worried about to check though. So, have her take a test if she's not gotten her period yet.