how do you know if you have glass in your eye? even if its the smallest piece?

i was just walking outside and it was kind of breezy and the street had dirt, sand and pieces of glass on the floor. i suddenly felt a sharp pain in my eye and afterwards i didn't feel any pain. i'm scared a tiny fleck of glass got into my eye and that it will travel its way up to my brain and kill me. what symtpoms should i get before going to my doctor? im still not sure.