Adjustment of Status - I-485

I had my AOS marriage based interview yesterday at the ATL field office.
I didn't get approve on the spot because an additional document is needed, and he gave me a paper saying that additional documentation is needed. He told us, Once we get the letter in the mail and send it back with the document ,
He also said he will need to check on my medical because Doctor may sent the previous version. One he check on it, if everything is good with the medical exam and once he get the document from me, He will approve my GC and it will arrive in the next 2 weeks after approval.

Questions asked:
-What is my husband full name
-What is my husband birthday
-Where he was born
-Where does he work
-How we meet
-When & Where did we get married
-How long we been married
-Do we have any children

(Same questions were asked to my husband)

IO didn't went through all the evidence i brought.
He said, He has no worries about our marriage, because he knows is real.

The only documents he saw were: My birth certificate, Our ID's & Passports, Our closing Documents, and our Wedding pictures.

Now, Just need to wait for the letter to get in my mail.

Does anyone knows, How long would it take for IO to send the letter?

Thank you so much everyone for everything!