Pregnancy
How early can a blood test detect pregnancy? OB/GYN in Seoul, Korea
The short answer
A blood test for hCG can detect pregnancy about 8–9 days after sex, a few days earlier than home urine tests, which usually work from about 10–14 days. A negative result very early may need repeating a few days later.
Blood tests also give a number, which helps track early pregnancy when repeated. See pregnancy test.
Answered by Dami Women's Clinic (다미산부인과의원), Yeouido, Seoul · Dr. Ko Sang-hyun, OB/GYN. General information, not a diagnosis. Emergencies in Korea: call 119. Medical disclaimer · International Patient Center