Like nikki said, no. At least not 100%
it can take it a long time to detect pregnancy, so the best way is to buy some more preg test, preferrably 2-3, take one in a week, if it came out negative, then take another one in 4-5 days, if still negative, take another one 4-5 days to a week later, if still negative. There is not that big of a chance that u r preg.
But u know that getting a blood test is the sure way to know for sure