Horrible abdominal pain

Hi everyone I am (28) f and since last night I’ve been having horrible pain that started near my belly button to the right side of stomach. It feel like pulling sensation, when I sit it hurts. I went to the urgent care this morning because it was not going away. I have been constipated but would it hurt this much??

It feels like tight? Pulling; feels like it inflames and goes back down.

At urgent care they did urine test (all came back good)

Blood work on liver, pancreatitis and so on.

Called me back and said numbers are great.

They did x rays (waiting for results) (in case it’s from constipation)

& told me to ask my primary doctor for ultrasound.

My question is, if she said my blood work came back good what will the doctor be looking for in an ultrasound? Thank you