Go to ER
If the pain is unbearable, or acutely worsening, yes you need to go to the er. They might do the ct there to evaluate the cause of he abdominal pain
Don't rely on them to necessarily provide a definitive diagnosis, as the role of the er is mostly to diagnose and treat life-threatening conditions. Anything that is not dangerous and can be worked up later will be deferred. Nonetheless, go to er.