Unsure

My fiance and I have been trying for months to conceive. Recently ive taken 6 first siganl pregnancy test and the first 4 were very faint and the 5th and 6th were much more darker. I bought some digital test from walmart and tried it. (Didnt use fmu) and it said not pregnant. And me being crazy, i opened up the test and saw two lines. One was very faint but you can tell its there. Its thick as well. What do you think?