Wait a few days. I took a test when I was a day late that came back negative. I took a test a week later that came back positive
Wait another 2-3 days if you havent started then check again. If its negative you probably just skipped a period or your cycle could be changing. And even if it has never happened to you it could still happen.
I'd wait a few more days before going for a blood test.
I had taken 3 tests and they all came up negative. I had to go in to get blood taken and tested to get a positive. Even though I hadn't had my period.