hCG (human chorionic gonadotropin) starts to rise very soon after implantation occurs. Specifically, hCG production begins about 1 to 2 days after implantation. After this initial production, hCG levels double roughly every 48 hours for the first several weeks of pregnancy. However, even though hCG starts rising this early, it may take about 7 to 10 days after implantation for hCG levels to reach a concentration high enough to be detectable by most home pregnancy tests. More sensitive blood tests can detect hCG as early as 3 to 4 days after implantation, but urine tests usually become reliable around 10 to 12 days post-implantation. Implantation itself typically occurs 6 to 12 days after ovulation. In summary:
- hCG begins rising 1-2 days after implantation.
- Levels double approximately every 48 hours in early pregnancy.
- Detectable levels for sensitive tests might appear 3-4 days after implantation.
- Most home pregnancy tests become reliable about 7-10 days after implantation.
This timeline aligns with implantation occurring around 6-10 days post- ovulation, and the earliest pregnancy symptoms may also begin around this time due to rising hCG.
