Hi Raean! Your temps can continue to rise for several days after O and will fluctuate some as the days go by. Basically they'll rise to a general temp (like from 96.somethings pre-O to 97.somethings post-O) and will stay elevated until AF arrives. However, if you caught the egg and get pregnant, your temps will remain elevated throughout your pregnancy. (This is a part of the reason why pregnant women are always so warm, their body temp is naturally higher than someone who isn't pg.)
Seeing that FF changed your O date (and I think they are correct on this because your temps have been consistently higher the last few days), I would wait until at least next Saturday to start testing. You'll be 11 dpo then and even that is sometimes too early. And don't worry if you temp drops some one morning, it's perfectly normal, even in BFP charts, for your temp to fluctuate.
Good luck!!!