Your link has two http's in it, and you don't need the bit at the end.

I think you O'd on CD15, and the temp drop on CD18 may have been because you didn't take it at the right time, or were sleep deprived. It is too early for an implantation dip. Your temps are nice and high, if you had on CD13, 14 or 15 then I'd say you are in with a chance.

FF probably didn't give you a coverline at CD15 because you didn't have enough temps before that date. Try putting in 4 or 5 fake low temps from about CD9 onwards and it might change the coverline and ovulation date for you.

Good luck!