I agree with the above poster. It took me a week to get a positive test. Leave it a little longer before re-testing
it could still be a little too early at 1 day late for your period, especially if you ovulated later than usual. if you still think you might be pregnant leave it until you are a week late and then re-test. And make sure you test with first morning urine. I didn't get a positive test until I was 1 week late with my 3rd baby, but I just knew I was pregnant.
Good luck.