How late can you be and still be pregnant??

Sarah • 29 • Baby Girl #1 11-3-19💕 • Baby Girl #2 2-8-21💕

I’m currently 12 days late but got a negative test a couple days ago. I’m afraid to test again and it be negative. How late can someone be and still be pregnant but get negative tests? There’s absolutely zero signs of my period coming at this point and I’ve never been more than 5 days late before.