Can you take a pregnancy test 14 days after sex and it be accurate?

Seven to ten days after a missed period, regardless of when you had intercourse. If you don't miss your period, you're not pregnant

That would be too soon. It takes about three weeks from a fruitful sex act for the fetus to make enough HCG to result in a positive test. If you miss your period by 4-5 days, do a home pregnancy test. If the result is negative repeat the test 4-5 days later unless you get a period by then. Use first morning urine and follow the instructions carefully. Wish you good health!