8 days late

Mi

I’m currently 8 days late for my period. I have never been late more than 1-2 days. And 2 days is pushing it. I keep getting negative tests. There was one frer 2 days ago that had a faint positive at the top of the test but the line did not run all the way down. But today was negative. Do I wait another week or do I call my dr now for a blood test? Has this happened to anyone else? Is it too late to get a positive at this point?