I'm 14, I'm a girl, and today I had the worst pain in the lower right of my stomach. it just randomly started when I stood up & it felt like a really concentrated pressure in that one spot. it was off & on for 3 hours and at points it hurt sooo badly. i have never experienced a stomach pain like it. i thought maybe it had something to do with my appendix but once I got home from school it completely went away. it hasn't hurt for like 7 hours. should I be worried ?