Has this ever happened to anyone?

I took a dollar store pregnancy test and it was very faintly positive. Then I wanted to see if the line would get darker so I bought a fee Walmart 88 cent ones. I took and and when the test was almost completely don't I saw a darker red/pink line, I was so excited. Then when it was completely done the line disappeared. I took two and the same thing happened both times. Has this happened to anyone else? Were you actually pregnant?