Minecart Glitch

So I was riding one of my Subway Stations (by minecart (no mods)) and all of a sudden, I appear (while riding) in the ground and my head is outside. I've made a screenshot and did not want to show my skin (I don't know why). I do not know if someone else has reported this BUT I've searched it and there were no results. I hope this isn't a major bug or something.