Clinical guard sensitivity?

I’ve gotten faint lines with the clinical guard pregnancy strips for 3 days now. Once I saw that line I couldn’t help but test every day after 😂 Anyways I took a first signal because it seemed the clinical guards weren’t getting any darker and were already extremely faint anyways. I know it’s there bc I posted it and people agreed there was a line.... But the First Signal was negative. Do y’all know what the sensitivity for the CG is? I’m not sure when I ovulated. My app says AF is due tomorrow but I’m not sure I trust that date since I recently got off BC almost two months ago.