Seems fast to me as well..
Are you using filter media from an established tank? That would speed things up.
Another possibility, I hate to say, is human error. You wouldn't be the first (or last) person to either muck up the test or misread the results.
I can identify with the excitement of cycling your first tank. Just be patient and let the process happen
. I made a ton of mistakes that could be traced back to me rushing things (still do sometimes).
Also, I wouldn't bother testing every day for the first couple weeks. Things aren't (typically) changing that fast, so unless you really like testing your water (which I kinda do) youre just using up testing supplies.