Hi. It sounds like the Pizza crust that you swallowed created some soft tissue injury and swelling around the voice box region and maybe even in your food pipe. This may be a simple abrasion that goes away in a few days (if your only symptom at present is a feeling of something sticking in your throat). On the other hand, pain in the chest radiating to the back between the scapula (shoulder blades) is a sign of esophageal tear and an infection called as mediastinitis. I would closely watch for fever and if you develop one then you should go to the ER immediately. The body is unable to differentiate between the sensations due to injury or if something is really stuck. They will both feel the same. So if the pain is not worsening since you swallowed the small piece of pizza or there is no new site of pain or fever and if you can swallow your saliva comfortably then you can wait for a few days to allow the injury to heal. Else you must visit an ENT and have your voice box visualised under endoscopy (Videolaryngoscopy) to confirm the findings.