Hills Like White Elephants

I honestly didn't like this story. It was kind of confusing. I read each section several times and still don't get it. I don't understand what was the big thing that he kept asking her is she sure that's wants to do. At first I thought sex. But then it said that they had been to whole bunch of hotels together. So I figured if they were going to do it they would have been had sex. But then he got the bags in the end. So I figured that maybe it's because she doesn't know if she wants to live in Barcelono permenantly and make that their permenantly address. I'm kind of confused.