BFN 11 DPO then faint line 12 DPO

[Hopeful2017]

Hi ladies,

Has anyone been sure of ovulation dates and had negatives up until 11 DPO then followed by a faint positive 12 DPO? On my previous pregnancy I had BPF at 9 DPO.

We did an IUI so I am sure of dates but I’m wondering what are the chances of this actually being possible so late in the game?
Anyone ever been in the same position?

I had a blazing negative in the evening of 10dpo once even though I was sure I was pregnant because I had been feeling so off since 7dpo. Morning of 11dpo was a positive.