Could she be pregnant?

I hope I understand your situation clearly. You said she begins taking her active pills after she has stopped menstruating. I'll ume she takes the typical 21 days active, 7 placebo pack. In a natural cycle, day one begins on the onset of menstruation. If you had six days after her first pill and she missed one, that means you had on day 14 of her cycle, which is typically when ovulation occurs. As far as timing goes, that was fairly risky, and missing two pills in a cycle also increases your chances of pregnancy. However, the fact that you withdrew prior to ejaculation greatly reduces the chances. A pregnancy test is typically not positive until the first day of a missed period, or about day 28. No pregnancy test will be positive 4 days after , because the fertilized egg would not have implanted yet. Remember that the "period" a woman has on the pill is not a true period; it is just bleeding due to the drop in hormone levels, so that would not let you know for sure. She can have a blood test done at a clinic or doctor's office which is more sensitive and can detect pregnancy hormones sooner.