Even though Joss Whedon himself has said ‘there will be no after credits scene” Marvel may have different plans! Check out the video below!
Link to the original https://youtu.be/RZ1urzF56aY
Also reports are coming in of the mid credit scene as well: MoviePilot
The film does however feature a mid-credits scene, which is after the cast credits and before the roll credits (which go for about 10 minutes). According to an IMDb poster on the Age of Ultron Message Board, the mid-credits scene goes like this:
“The mid credit scene shows a dark scene, the point of view from inside a container. As it opens up, you see Thanos reach in and pull out the Infinity Gauntlet! It doesn’t have any gems on it yet. But he does say: “I guess i’ll have to do it myself” as he puts it on. I’m guessing this is a reference to Loki or The Collector or Ronan or someone failing to get him the gems…”