TCOYF tells us that if we make it to 18DPO with high temps and no AF, that there is a good chance that we're pregnant. Has anyone made it to this point with a BFN? I feel like i'm going crazy. Every test i've taken has been negative. I've never had a luteal phase longer than 16 days and today is 17DPO. My temp dropped even with the cover line today, but no real signs of impending AF (I usually spot a few days prior and have very distinct cramps).

I know it's very rare to have negative urine tests this late and actually be pregnant. It seems like most of the people i've seen on this board have had BFPs 8-12DPO. Anyone with a similar experience or a super late positive?

my chart for reference: My Ovulation Chart