A little help here.

I'm so confused. I was getting peak clearblue digital tests 2 days after my period ended. It didn't seem right so I purchased these strips and a thermometer. They arrived over the weekend and I immediately got two dark lines when I tested Sunday night. Any thoughts on what is happening here? I'm thinking the digital tests were incorrect, maybe faulty? So confusing, I'm been going off what the digitals say but now I think that may be the problem. AF ended on the 19th and was 4 days.