For the most accurate results you should wait until your period is due to take a test (some can test up to 5 days before a missed period...but they're not 100% reliable for a few different reasons..the tests are reliable, but the results might not be), but if you don't know when your period is due you can take a test 14-16days after your last unprotected sex and get a fairly accurate result.
Most test claim they can tell you 5 days sooner, which should be about 10 days past ovulation (5 days before your period) but a lot of test will give a false negative at that time if you are indeed pregnant, If money is not an option, I would suggest 10 dpo (I started at 7 and didn't get faint pos. till 10), if you don't want to spend a whole lot of money, try the day before and day of you period. Good luck and hope this helps!
I agree with trying...it depends on how much money you want to spend, lol. i'm one of those lucky ladies who got a positive at 10dpo with my daughter and 9dpo with this pregnancy, but that's not very common...what trying suggested is a good idea if you dont want to spend too much money. I went through a lot of money buying tests after the first faint positives to make sure they weren't false positives and i should've just waited until my period was due both times LOL.
Last period 8,31,13 when do i take the test