Could she get pregnant?

sorry to burst your bubble but , yes she can get knocked up . even if she got her period their is a chance she could be pregnent . so much for safe sex .

The pill is about 99 percent effective at preventing pregnancy, so the chances would be extremely low that she is pregnant, if she hasn't missed any pills in her pack.  Also, the only proven antibiotic to interfere with the pill is rifampin- so if she is not taking this antibiotic, you have nothing to worry about.  If she had a regular period, this means that pregnancy did not occur.  When you become pregnant during a cycle you would miss a period and implantation bleeding occurs.  This is usually pinkish and spotty and nothing like a period.  If the bleeding was not like a regular period, then pregnancy or an abnormal period is possible.  In this case she should see her doctor for a blood pregnancy test, as this is more acfurate than any home test.