Lets just pre assume: Given that you had your bio-done on nov 10th, you must had filed sometime on mid October and your priority date must be  somewhere between that time line. USCIS is currently processing the cases from September for  Virginia / DC field office. As far as your concern goes, your on the right track and  no need to be worried about. If the trend holds true in your case, you should receive your interview letter within 3 weeks.