You need to have it looked at immediately. I have a close friend who stepped on some glass when he was a teenager. The piece became embedded (it was quite large) and only emerged, on it's own, thirty-seven years later. The drill is a local anaesthetic (lidocaine), a clean slice and perhaps a stitch or two.
Well perhaps it is time for a visit to the Doctor to have it aken a look at...another way that works sometimes is get a large band Aid put some anti biotic cream on it and firmly press it onto the area. leave it to absorb, check it after 24 hours and do it again if the glass hasnt risen to the top of the wound.Best Doc though ....