Can someone explain this to me? OPK help

Nikki • Mother of A beautiful tomboy .. Two Angel Daughters. & TTCIng our rainbow baby 🙌🏻🌈

So I am on CD 17 of my cycle.. I have been testing two times a day with OPKS. I decided to take a digital one since I got 2 positives today..

Snd it came up negative. So I took the stick out and saw that the line is barely even showing on the digital one.. but on my cheapies, there is a positive line.. I’m so confused. Can anyone give me any advice or something?