With some sensitive tests, and depending on when you ovulate and when implantation occurs, women can get a positive test at 8 or 9 days past ovulation, which would be 5 or so days before their period if they have a 14 day luteal phase. Personally, I would prefer to wait until a missed period to test, as it still happens that sometimes one will get a positive on a very early and very sensitive pregnancy test and still get her period at the usual time. I don't think I could handle that myself, so I tried to avoid it after my first couple of months of very zealous early testing.
Edit: In other words, yes, with some tests and under certain circumstances, you can get an accurate result from a test taken that early. Some women (like me) choose to wait until after their period is late anyway, though. Good luck!!!