Get yourself some condoms, first of all! That's the responsible thing to do. You can get pregnant if you have unprotected intercourse even if you don't ejaculate. The penis emits pre ejaculate which is 'enough'.
But she has now take Plan B or emergency contraceptive and did so within 72 hours of both times of having unprotected sex. So, she is probably all good, not pregnant if you used it correctly.
However, the pill is a big dose of hormones which is how it works. It WILL prevent pregnancy from occurring but then all those hormones are sill in her system. So, women are irregular for 2 to 3 months after taking the EC. That means she can have a long cycle with late period, spotting, etc. That's normal after emergency contraceptives. Keep in mind that it also throws off when she will next ovulate so it is more important than ever to use solid protection now.
Pregnancy tests are accurate 2.5 weeks after sex. But she sounds to just be experiencing the normal side effects of emergency contraceptives.