I’m on day 4 of prednisone. My chest is tight and my stomach is cramping. I have a headache and I’m feeling anxious. Is this normal?

Not certain why. you are taking prednisone. The "stomach cramping" could represent one of the common side effects of steroids which is gastritis or inflammation of the stomach lining. As soon as possible consult with the person treating you as to the diagnosis and only take prednisone with food and preferentially with something like zantac or famotidine daily.