16 DPO:BFN but no AF?

Hailey

From my research it seems to me that you can get a 100% accurate result 1 day after your missed period or anytime after 14 DPO when taking a home pregnancy test. I tested at 16 DPO and 1 day after my missed period with a BFN. Has anyone ever tested negative, just to test positive much later? Or would you say that I am 100% negative and prob just late on my period for other reasons? 🤷🏼‍♀️