I got interviewed by National Background Investigation Bureau for the Army. How long does that process take before they contact my recruiter?

PVT (Join to see) No one can tell you how long it will take because it will vary on your background as to what they need to investigate..

https://nbib.opm.gov/faqs/

How long does a background investigation take? View less
The timeliness of a background investigation depends on the type of investigation required for the position. Depending on the type of background investigation, the scope of the investigation varies. Additionally, each individual person’s background varies which effects the number of resources needed to complete the background investigation. The need for a security clearance may affect the time it takes for your agency to adjudicate the completed investigation. Each background investigation requires that specific investigation components is completed. Although all investigations vary, you can find the overall average investigation timeliness in the Agency Performance Plan and Report at: https://www.performance.gov/OPM/OPM.html. We anticipate quarterly metrics will be available beginning in March 2018.