Need some more advice..

Shyann • Mama💗😇💓

My period was due the 13th, it's now the 24th and no sign of it coming any time soon. I've taken several pregnancy test and they all come out negative, BUT a few minutes to a couple hours later there's a small faint line, which has never showed up on all my old tests. I am cramping in my back but nothing like period cramps, I'm never late on my period and I know by cycle almost 100%. So could I be pregnant? Is something wrong?