Faint to dark line

Loren

Periods are irregular. I had a period September 16th and then October 21st we’re the beginning of my period. I took a pregnancy test 21th November and it was negative. I took another one on the 25th and it was very faint so bought another test that night and it was a littler darker. Took another test 26th,27th and 28th and it’s getting darker. How many weeks do you think I could be?