I wish I could give you a clear answer, but it honestly just depends. It depends on the workload at that office, how fast or slow the adjudicator is, and other factors beyond anyone' s control. Hopefully it won't take more than a month or two before your case moves forward. However, it gets to be six months and nothing has changed with your case status, contact the National Customer Service hotline for an update.
This general advice does not create an attorney-client relationship.
If the reply was sent with tracking you will have a record of when it was received. You can contact USCIS customer services after 30 days for any information. The time to wait is related to what asked for --- ie. info on foreign country residences or police reports can take a long time.
Legal disclaimer: The statement above is provided by CC Abbott is based on general assistance and not intended to be a legal opinion because not all the facts are provided. The person requesting information and all others reading the answer should retain an attorney who is permitted by the state bar within the jurisdiction who can examine the complete facts and provide a legal opinion on your case. All information provided in the above answer and other information provided by CC Abbott does not create an attorney/client relationship within any state of Federal law.