Do I have appendicitis, a Urinary tract infection, or something else?

I have pain which seems to be coming from my rib cage and maybe a little below it, its not as much as a pain, but more of a slight uncomfortable feeling near my right rib cage, I've looked at symptoms of both, my mom who's a nurse thinks I have a urinary tract infection because the pain is coming near my kidneys, and I have been peeing sometimes once every hour, today I had about a 6-7 hour break in between pisses. She started me on some antibiotics today and said if it doesn't feel any better in about 1-2 days then to go see a doctor. Although if it is my appendix I am worried about it bursting, any help would be greatly appreciated thanks :D