No, period with neg pt

Maria
So I was supposed to start my period on the 8th according to the <a href="https://play.google.com/store/apps/details?id=com.glow.android">glow app</a> my lmp was June 7th, I did 2 test and both neg... small cramping and just a small tiny spotting but my pad doesn't get no dirty only when I wipe it appears... anyone know wtf is happening lol