Seeing nothing :/

Glow told me to test this morning, so I figured I would give it a shot, but I got nothing but a BFN :/ 12dpo and seeing so many BFP's from others at this point in their cycle so I'm becoming discouraged. I know I'm not out until AF shows, but I'm feeling less and less confident as the days go by. I have a 28 day cycle and AF due 10/6, but I got my positive opk on CD15 so glow changed my start date to 10/7 so I don't know exactly when I should be expecting AF now, I'm so confused?? 😩