If my last period was the 3rd of august when would my next one be and im ttc can i do a test now a sensitive one?

You know: most women know how often they get their period. in a typical 28-30 day cycle you ovulate on day 14-16 and conceive somewhere about then. a preg test should be positive by day 20-21 usually if you conceived.

Good luck: Try to wait if you can, but yes if you are pregnant it is possible that a test could already be positive. 1-2 weeks after you missed period is more reliable, but a + test is reliable, not a negative one.