when will i get the first response letter from USCIS? How will i know if they need some more documents from me? If some documents are missing, will it affect my priority date?

[quote=Anu Arun;2467]when will i get the first response letter from USCIS? How will i know if they need some more documents from me? If some documents are missing, will it affect my priority date?[/quote] USCIS is currently processing I-130 application. If you add your case to the tracker http://www.mygcvisa.com/tracker/ you can quickly check you case status and any updates. If they need any documents, they will send an RFE. If documents are missing, it will not change your PD. Your PD is fixed.