Hi ! The first thing I will think with your symptoms and signs mentioned is an attack of appendicitis
if there is no history of its removal earlier. For this, you have to consult an surgeon and get clinically examined who may suggest you a few routine investigations along with an ultrasound
The next possibility is food poisoning
. You may get to have loose stools/vomiting if the infection is severe.
Next possibility is a pelvic inflammation. For this you have to get yourself examined by your gynaecologist.
The ultrasound will rule out if there is any calculi in your urinary tract
which may also give rise to such symptoms.
A diagnostic laparoscopy
is an option if everything else fails to diagnose the problem.
Please consult your doctor and get investigated. Good luck.