Hello, I Am A 34 Year Old Female And Have

Hello, I am a 34 year old female and have been having pain in my right lower abdomen and pelvic area, with nausea, feeling like I am in the verge of throwing up, and diarrhea after I eat anything for 3 days now. Took a pregnancy test and it was negative so I know it's not pregnancy.. I am not sure what I should do, or what this could be.