and it may actually be sooner. I am not certain, but I recall getting AF within 4-5 days after stopping meds but I was repressed (I forget the correct terminology) and I did not ovulate nor have any follicles, so I think it varies from person to person.
One time, I did do back to back FET's, November 11, and then December 12, both were unsuccessful, but I had other issues that needed to be worked out.
As to your second question, many RE's like to wait a cycle or two, but there is really no medical reason to wait. Once your lining has shed (you have had your period), you can begin building it up again to prepare for the embryo to snuggle in. Hopefully your RE will agree with this timeline. Good luck, it's so frustrating when you have to wait even longer than you thought