Yeah the day after your peak is the first day of your luteal phase and the start of the 2WW....how long is your luteal phase normally? I would think it was accurate last month - it is normal for your Ov date to shift month by month by a day or two - or even a week!
You can have a 28 days cycle every month but still Ov on different dates every month too - are your cycles normally regular?
The CBFM gets more accurate the more it's used, because it remembers the previous months data. So your highs (in theory!!) should decrease - by month 3, I had 3 days of highs then the two days of peak, then one high and back to low. Compared to month 1 where I had something like 17 days of high and no peak! lol
Bizzarely, I have just lent my machine to my mate who is TTC, this is her first month and she got peaks on CD9 too - same as you did!! It threw her into a right panic because it came so much sooner than expected, but I was well jealous because I didn't get any peaks until month 2!
xx