Why won't my 3ds read game cards?

Hi, I recently was playing SSB4 on my 3DS, ejected the game card because I wanted to switch to Pokemon Omega Ruby because I was getting tired of smash, and when I tried to put the Pokemon game in the slot, nothing would happen. I turned my 3DS on and off, tried other game cards, did the paper in front of game card trick, and none of it has worked. I love my 3DS very much and I'm on it almost all of the time. If any one can help with this please respond, because I want to make this work ASAP! Thanks!