Blood tests

So my period is currently 8 days late. I’ve always had a regular period, it’s been consecutively on the 13th for the last 3 months. But nothing yet this month. All tests have been negative other than I think a false positive on an equate brand since every test after has been negative. My question is has anyone gotten a positive test through blood and not urine? I go tomorrow to have my blood drawn! Have had some pregnancy symptoms so it’s really throwing me off.