FF Question

I have quick question about FF/ovulation, on FF which day does ovulation actually happen, the day before your temp spike or the day of your temp spike? I manually overrode the CH because I had conflicting fertile signs but I know I ovulated based on my temps...my CM just confused FF.  This will just effect whether or not I am 10 or 11 DPO which will effect when I will do a HPT. thanks!