Traveling with Advance Parole. PLS HELP!

Hi everyone,

We are Canadian Citizens living in the U.S. My dad has applied for our green card through his employer and we have been waiting since 07!

I just turned 24 and would like to visit Canada while waiting for our green card.. I am applying for an advance parole and was wondering if I would run in to problems going back to U.S.. what are the reasons they could deny me entry? Just kinda scared since I have not left the U.S since 07 and have never used an advance parole.. im worried going back to the u.s since I won't be with my parents and get denied back in.

Also going back the U.S, what else do I need other than my passport and advance parole? do I need to show ties to the U.S like school/work etc.?
If I get denied entry what happens to my paperwork thats in process? Im also planning to stay for 3 weeks.. is that too long?

Thank You in Advance to anyone that can help me.. This is probably the first time in my life that I had to worry about visa and documents that can potentially mess up my life. Being an Adult is stressful!

Advance parole (AP -- I-131) serves 2 purposes. First it assures CIS that you are not abandonning your GC process (i trust that you have an I-485 petition already filed, and are merely waiting for its approval)

Second, it tells the border that while you have no non-immigrat status to enter US, you are an "adjustee", which is perfectly fine. It is important not to leave US without this document, otherwise your I-485 could get cancelled.

Once you have this AP, There is no reason for them to deny you entry, so relax. You do not need to show any ties (you aren't a permanet resident yet). You can stay out as long as you wish, just make sure you come back before the I-131 expires (and preferably before your GC is approved).