3 days late

kay

I'm 3 days late and this would be my fourth child. I absolutely feel like I'm off. Nauseous. Slight headaches. Cramps. Lower back pain that feels like pinching. I took a pregnancy test yesterday and it was negative. With my last three, I didnt have any symptoms until 2nd trimester. Could I have concieved late? Or what? It's so frustrating.