BFN after late period

Queen

I took a test 3 days after missed period with a cheap test and got a BFN … so then I thought maybe I should get a more expensive/accurate one. I tested again with a first response… again I got a BFN . No faint lines. I’m now 6 days late and wondering what’s going on 😩 I’m wrecking my brain. Any one has or had a similar problem? If so, what was the outcome? Oh and btw I’m a mother of 4 already!!!