When should i take blood quantitative beta hcg test after intercourse/sex?is it accurate enough if i do that 2 weeks after intercourse/sex?

3 wks after sex: There is no need to rush. A pregnancy test gives a reliable result 3 weeks after sex (3 wks after when conception might have occurred), or 1 week after missing a period. If done sooner, a positive result is likely real, but a negative result may be due to testing too soon, and thus lead to a repeat test. If a woman gets her normal regular period, then she is not pregnant, and a test isn't needed.

It depends...: A blood test is fairly accurate about 7-10 days after intercourse. Qualitative (not quantitative) blood tests are usually used to detect pregnancy. Home urine pregnancy tests are about 99% accurate if it has been one week since a period was missed. They may detect a pregnancy earlier than that but are less reliable to rule out pregnancy.