How soon after unprotected sex can i take a pregnancy test?

Can or should ?: To turn a test positive the sperm/egg need a couple days to meet up. If conception occurs it takes a few days for it to form the cells & move to the womb to implant. After implantation it takes a few days for the cells to create the chemicals that turn a test positive. You can test any day you want. It is unlikely to show a true positive until about 2 wks after exposure.

See below: Conception occurs within day or so of the sex. It takes about 3 weeks for the embryo to make enough HCG for a positive pregnancy test. Blood test may be done a day after a missed period. Home pregnancy tests should be done 4-5 days after the missed period. If the result is negative repeat the test in 4-5 days. Use first morning urine and follow instructions for the test carefully.