Well I'm 3 chapters and 12000 words into my book and I still haven't decided on an main antagonist. I was thinking about having my character's past experience with people affecting his decision making in his present be the antagonist but It seemed a little too non antagonizing. I also considered having maybe one of those characters from his past come in and be the main antagonist but not sure how I can relate that to what my story is currently shaping into. What do you guys think about just having one's past experiences be the antagonist? Plus when do you think is a good time to introduce it as the clear problem of the story?
You can have practically anything you want as an antagonist. Look at the movie The King's Speech - there's no personified antagonist at all, not a single "bad guy." There's only the problem of the King's stammer. That doesn't sound like much of a problem, but it resulted in a great movie that won Oscars for Best Picture and Best Screenplay. The point is, great drama can come from any conflict. There's no reason you can't get great drama from your MC dealing with his past experiences.
Orphaned girl came to live with her grandfather. But girl's parents were thrown out by the grandfather when he was young and arrogant. He is now old, alone, and kind of needs someone like her to be around. She is just 17 and needs him to provide her food, shelter and guardianship. But none is willing to accept this because of their PAST. So, who is the antagonist here? I would say "their past". This was a beautiful story I read about how they defeat their past to come closer. Your antagonist need not even be a walking, talking character even though one might argue "their past" can be treated as a character.
I completely concur with the above two posts. They answered your first question well, so I will tackle your second question: When should you introduce this antogonist (or even better way to put it: conflict). 3 chapters already in, and no antagonist I feel is a bit too long already. If there is no conflict by that time, I'm not certain you can keep your readers long enough to get into the fourth chapter (even if you introduce a conflict in that chapter). Especially if those 3 chapters together form 12k words. If there is no conflict, how have you filled these 3 chapters? This might give us a clue on what's going on here,
