What could be wrong ?

So my 4 week old has had gas that smells like she poooed very often and is more fussy than usual. She cries like she has a stomach ache by pushing and crying (she has normal stools so she’s not constipated) and she’s feeling warm i been checking her temputure and it’s always varies between 98.1-99.6. She has a appointment with the doctor tomorrow but what could it be? She drinks her bottles like normal (she’s formula fed enfamil gentlease) she drinks 4oz every two hours and she has normal wet diapers but she’s fussy and has slight temperature