In wich day after sex the pregnancy test is true?

Positive. If you got pregnant right after ovulation, which is day 14 if yours is a 28 day cycle, a blood test, b-hcg, will come out positive within a few days. A good urine pregnancy test will be positive within a few days of an expected missed period. The best time to do the test is usually the first morning urine.
Pregnancy test. While a few home pregnancy tests may be sensitive enough to show a pregnancy on the first day of a woman's missed period, most test kits are more accurate about a week after a missed period.The ovum lives underutilized for less thn 24 hours after ovulation.Fast-swimming sperm can reach the egg in a half an hour, while others may take days. The sperm can live up to 48-72 hours.