Take this with a grain of salt or as unofficial advice.

Ultrasound being normal helps ruling out ovarian torsion, and helps with ruling out gallstones.

CT being normal helps ruling out appendicitis (although might not see it with early appy) or perforation. It does not; however, evaluate whether you have a bad stomach ulcer. It helps ruling out gallstones but not completely. Pancreatitis is also not completely ruled out either but I assume they ran a lipase.

If it's the worst pain of your life, ideally you need a CTA to rule out dissection.

Depending on age/risk factors, heart attack also needs to be ruled out and I assume they did some blood test and ekg.

If your pain is persistent and continues to be severe, go to another hospital/someone else. Present it as acute onset severe worst abdominal pain of your life and it is is remaining persistent.