usually in inital interview,you are required to appear with your spouse ,but if the immigration officer have
some doubt,he/she may schedule the second interview,
and question you & your spouse seperately,& compare your answers whether same & different,finally verify if
the marrige is real.
If the immigration officer thinks the marrige is real,
he/she may issue a I-551 stamp on your passport, as a
temporory envidence of green card, the green card will
be sent to you in a few weeks,if your background check
has been compeleted at that time.