How early can you test for pregnancy after intercourse? Read on to learn more.
A pregnancy test detects the presence of the pregnancy hormone hCG (human chorionic gonadotropin) either in the blood or in the urine. The hCG in the urine comes from the hCG in the blood after it was filtered through the kidney.
After ovulation, the egg gets fertilized and travels through the fallopian tube toward the uterus. This travel takes an average of a week. Implantation, the attachment of the fertilized egg in the lining of the uterus, occurs on average about a week or later after ovulation/fertilization, but it can happen as early as six days and as late as 12 days after fertilization/ovulation.
At the time of implantation the placenta starts making the pregnancy hormone hCG, which then enters the blood stream.
How early pregnancy can be detected depends on the pregnancy hormone hcG which can be detected in the blood about three to four days after implantation. Urine hCG can be detected about two to three days after blood hCG can first be seen. Detection of hCG depends on timing of implantation, so hCG can normally be detected in the blood between nine and 16 days after ovulation (HPT: 12-19 days after ovulation).
Blood Pregnancy test: If you are pregnant then the blood pregnancy test is usually positive within 3-4 days after implantation or about 9-10 days after fertilization and ovulation.
Urine (Home HPT) Pregnancy Test: The early positive urine pregnancy test will usually not become positive until 2-3 days after the blood test, and in most women until a missed period or about a week after implantation. Many manufacturers of urine pregnancy tests want you to believe that the urine test is usually positive before a missed period, but only about 25% of pregnant women will test positive with the HPT 2 days before a missed period, and about 40% the day before the missed period.
Reference: Baby Med