Yes. However, I will tell you this - college is a really stressful time for a woman. On these message boards alone I've seen at least 4 other boyfriends posting about their gf's missed period and they were also college students.
Stress and massive change as experienced in moving away to college can cause a person's monthly cycle to be thrown off.
How late on her period was she when she took the pregnancy test? If she has not started in a week, have her take another one - but you can believe the negative result now if her period is late.
Good luck and relax a little.