Negative ovulation tests?

Alexai
I took an ovulation test last Thursday and it was almost as dark as the test line then I was out of tests until Sunday night. When I tested again, there was no line Sunday and Monday then yesterday I had a faint line. Now today it's so faint it's barely visible. I BDed like I was supposed to but now Glow keeps pushing my fertile window out 2 more days. Do I keep testing? I feel like I've already ovulated. ???