I am not sure what is the question about, but i think it's like:
1) I am having a meeting next week ( I will have this meeting, and it's for sure)
2) I am trying it! (I will try it, and nothing is able to stop me)
3) I am watching the game on Saturday ( I am going to see this game, and that's for sure )
The present progresive is used for future events only when it's certain it is goin' to happen, or you think it will happen for sure, at the moment you are talking about this.