Job Fair Interview Question?

Hi, I just recently went to a hospital where they had a job fair going on. I went and got interviewed with some basic questions and was not that long. They then took me to another room with other applicants and told me there was a second process to the interview and that it might be awhile to get called on. I waited for a couple of minutes and then they called my name, but to only tell me that there were a lot of interviews going on and that he will call me back on Monday and if not by Tuesday. I am kinda of confused on how I did because I thought I did well and was surprised that instead they said they will call me back next week. What does that mean? Am I going to get a chance to interview with them? or How come I was not forward to the second part? I hope I get a call back then and see if I got an interview. Does anyone know what this might mean? Thanks!!