4 days late and BFN

I am never ever late. Every now and then I’ll be a day early or a day late and get it very early the next morning. But never 4 days. I took a test this morning and got a BFN, I’m trying not to lose hope until af comes. I’ve hard extremely mild cramps today, also not typical for me. My cramps are usually like daggers to my uterus. How common are false negatives when you’re 4 days late? I’m praying, and trying not to lose hope. Please please send some baby dust my way.