Rainplace--5 months is the average for starting to lay. With the days getting shorter, it will probably take them a little longer than the average. But you probably won't have to wait too much longer. I had ducks that reached maturity about this time a couple years ago, and they started laying on Thanksgiving Day. When you're checking for eggs every day, it seems like FOREVER before they start laying. But it will be here before you know it.
I have ducks nearing maturity now. I am not even planning on eggs until after Christmas. That way, if they start earlier, I won't be disappointed! LOL
Have faith--it won't be much longer now!