need help!

So I'm 3 days late, 30 day cycle me and my partner been trying for over a ear LMP 11th August it's now 12th sep did a prognosis test on the 10th got a negative result and a clear blue yesterday with another negative result but I feel pregnant! I can feel my uterus cramping and stretching every day and I've had some pregnancy symptoms please help !! Has anyone else experienced this or anything like it ?