This trick has worked for me in the past. Take some Elmer's glue and spread over the splinter. Let it dry completely, then peel the glue off your skin in the direction that you would pull the splinter out if you could grab it. The splinter stays attached to the glue. Probably won't work since it has been a couple days, but if done right away it works great. One note however, there must be a tiny bit sticking up for the glue to get hold of or you have to use a needle to open the hole and let the glue in.