Adjustment of Status - I-485

Hello, my case is F1 got married to USC. I'm 22 and my husband 20. We were friends since childhood. I'm now living with my mom in law. The thing is they both cannot be able to sponsor me because they are low income. My uncle is a co-sign sponsor for me and everything is fine. The case is ready to be scheduled for an interview. The question is we are young and it can be hard for us at the interview. We don't even have money for a wedding. In fact, we could wait until we both graduate and have a job, but because of my F-1 status, we decided to do it now. But I cannot say like this to the officer if he askes us why we are married this young right? Please give us some advices!