It's different for everyone. You can try right away but it may take a few cycles. I would track everything that happens in your cycle. Cervical mucous is a good thing to look out for. If you have an abundance of it and it looks like raw egg whites...then get busy.
Good luck! Check out "deanna's plan". You can google it or it's posted at the top of the main page in this group!
I got mine out 9/26. First cycle was a little short but the last 2 seem to be normal. Yes chart you bbt and cervical mucous. It will definately help you see patterns. As to how long? Everyone is different and your body may take some time to build up it's lining inside. We are on month 3. Good luck to you :)