I totally tested negative at 8DPO, not even a faint line! Same thing at 10 dpo. Got a v-e-r-y faint hint of a line the night of 11 DPO and in the morning of 12 DPO got my (still faint but definitely there) BFP with FMU. Hope that helps and hope you get yours!
Oh and FWIW, I had a huge temp dip at 9 DPO and thought I was out- pretty sure now that that was my implantation dip! =)