Period but still faint positive?

I'm devastated as today af was due and it seems like I'm on my period now, i took a test anyway and it was still faint. I don't understand why this keeps happening to me😢 this is my 3rd consective chemical and I'm so sick of it😭 how do i go from getting darker positive tests yesterday to af today, I just ugh! I'm frustrated, heartbroken and so confused. Why won't my body work😔