Can we talk about the ending of Past Lives, please?

I just finished watching Past Lives last night and it's been bouncing around in my head since then. There was so much to the movie and for a directorial debut, wow, Celine Song really nailed it. There are a million things I could talk about from the movie but I really want to talk about the ending because it was left somewhat ambiguous. I love movies where they leave you room for interpretation and it feels like that to me.

!My question is, what do you think Nora was feeling that made her cry?!<

!While I was initially sitting with it, I was thinking it was because she clearly love Haesung and wanted to be with him but as I've sat with it I think she was crying because she was emotionally confused. She was overcome with the "what abouts" of her life. She is curious about all the questions that Haesung brought up at the bar about them, the questions that Arthur had when they were in bed together, the questions about her personal/ professional life of would she be "more Korean" or a different person had she stayed. I think she realized how that one decision by her parents set her on an enormous journey, exemplified by the shot of her walking up the stairs and Haesung going straight.!<

I don't know if there is a right answer about this but I loved how that simple scene pulled so much together. It was a beautiful movie.