Hamster bite - swollen finger. should i be worried about rabies?

Depends : If the hamster is a pet & housebound I have a hard time seeing how s/he would get exposed to rabies. The texas department of health maintains a public information website where you can look up the frequency of rabies in given counties & the animals that carry it. I would be more worried about other germs from the bite. If the finger looks inflamed you may need a course of abx. See your doc.

Get medical care.: It would be exceedingly rare to get rabies from a hampster. Hamsters can directly or indirectly transmit Rabies, Tularemia, Salmonellosis, Lymphocytic choriomeningitis virus, Dermatophytosis (ringworm, dermatomycosis), Rodentolepiasis and Hymenolepiasis (tapeworms).