What should you do if you feel like you may have swallowed a small flat piece of glass on accident?

I was drimking a glass of water and my lip got scratched on a chip on the lip of the glass. A couple of seconds later I felt a sharp scratching slowly go down my throat and into my chest. I didnt know what to do so I tried to push it down with water then milk then potatoes. The feeling that something was stuck in my ches went away but I still feel a bit of pain when I swallow. What should I do?