My period is 8 days late!

Sydney

So my period is 8 days late, according to the app, I’ve Ben getting my period on time with maybe 1-2 days off sometimes but very much on time and now I’m 8 days late. I took a test this morning and it came back negative. Is it too early to test? What are the chances of a false negative? How much longer should I wait? Has anyone else had a period come this late?