What Causes Left Sided Rib Pain After Treating Fever, Nausea And Vomiting?

Hi, My four year old daughter complained of nausea this morning and threw up around 11am. She has been miserable all day with stomach pain and slight fever, but no more vomiting until once more around 5:30pm. She s sleepy, lethargic, and confused. She s had plenty of fluids in between, probably five large glasses of water in total and some fruit. I just went in to check on her and her heart is racing. I counted beats with a timer and her heart is beating 160 times a minute. That s from a complete resting place. She d just woken up and hadn t even gotten out of bed yet. She s also complaining of a hurting pop right underneath the left side of her rib cage. She said it was like the pop when you pop your fingers but it hurts a lot. hould I be worried?