Well, the best idea is to get a pregnancy test kit.... a good
one can be gotten for less than $20, I think. They boast pretty
high accuracies of over 99%.
Check at Guardian pharmacies, Watson's, etc....
Our postings are by no means any substitute for a pregnancy test.
While those symptoms you describe may be those of pregnancy, for
all we know it could just be a case of the blues for your
girlfriend.