Late af and negative test?? 😕

Anissa
Have any of you ladies had a negative test after af was due and still been pregnant. I am on cd30 right now. I have 3 children and have always gotten a faint positive al least one day before af was due. I've been cramping for a week. My cycles have been between 25-27 days since I had a miscarriage last dec. I'm so confused? 
My tests this morning fmu