With my husband it took about a year from the time he sent within his application. We have a friend that get his in just about 8 months. Have you received your notice from the USCIS that they received it all the same? If not and it's been over a month you should bestow them a call.
My husband is currently applying for citizenship, we are so excited!!
6 months - we applied ultimate August and I have a moment ago go my green card