It most certainly does not mean you're out. All sorts of dips and spikes are possible when you've got various hormones surging.
Often there is a second surge of estrogen which can cause dips like what you are experiencing. It could also be an implantation dip. It's a touch early, but it has certainly happened before.
I would not discard the temp... FF should be able to work it's way around it just fine.
Best of Luck & Baby