Why did i get a faint positive result so early?

Kay

I had gotten a positive result 4 days before my expected period and i’ve taken tests and they were all positive but very faint. the first pic is all from yesterday (4 days before my expected period) the top test i took with my morning pee and the last two was in the afternoon and evening. and the last picture was this morning (3 days before my expected period)...has anyone else experienced this???