after interview at Newark, NJ - case pending for fingerprints Criminal Law

Hi,
I had my interview yesterday at Newark, NJ.

I am married to a USC. Everything went smooth. The examiner was kind and polite. But I didn't have my fingerprints done. The examiner scheduled an appointment for me to have the fingerprints done in April. He said it was the earliest as he could get for me. He stamped my passport as my case is pending for fingerprints
He said that it would take about 10 days to get the results since I have been there for photo and thumb fingerprint for my work authorization.
He also said that I didn't have to go back there (INS) to get my passport stamped since they are sending the Green Card very quickly now. And I should get mine within 2-3 weeks. (after the fingerprints done)

My questions is:

I was arrested 17 years ago but had my case expunged.
I had my fingerprints done at the police station near my house about 6 months ago and it came back CLEAR.
I would like to know if the fingerprints that I will take now will come out with the same results. In other words, do the INS go DEEPLY on my fingerprints - files? But I know for sure that the case is expunged and my case is no where to be found.

I am very scare to have any problem with that.

It is true that he can get the results in 10 days?
I heard so many cases here at the forum with people waiting for years...or is just when they are waiting for name check??

I appreciated your time and attention.
Looking forward to a reply.

Thanks again,

Hope63