There are many types of professional and home use pregnancy tests and their sensitivity levels for detecting HCG differ widely. Some over-the-counter home tests only detect 50 mIU’s of HCG. This means they may not pick up the pregnancy until well after the first missed period. Obria utilizes Consult pregnancy urine-based tests, and are capable of detecting concentrations as low as 20 mLU/ml as early as 7-10 days after implantation.
The production of HCG can vary greatly from woman to woman in any given week of pregnancy with as much as a 20-fold variation in individual levels. Some women with high HCG may come up positive on a pregnancy test very early, while others with low HCG may not test positive until well after the first missed period. In a recent study, reported in the Journal of American Medical Association, 10% of the 250 women tested had not even implanted by the first missed period. Therefore, their HCG levels were so low that no urine test could detect it.
Because the test we use at Obria Medical Clinics is so sensitive, it may pick up a positive result in as early as 7 – 10 days post implantation (21 to 24 days after the first day of your last period) depending on when implantation occurs and the client’s personal HCG levels. If HCG is detected at this early stage, the ‘test line’ is expected to be light, as HCG levels are just beginning to build. However, when testing this early (no matter the results), another pregnancy test should be taken a week or so after the first missed period. This is because, although the test picks up the presence of HCG, it does not guarantee a viable pregnancy. HCG may also be produced by an EPL or “early pregnancy loss”. This is an embryo that fails to implant properly in the uterus or is rejected by the uterus. This is usually followed by a normal or slightly heavier than normal menstrual period, which may be 2 to 3 days late. HCG levels may rise in the week following implantation (second week of conception) like a normal-term pregnancy. When EPL occurs, HCG concentration in the urine reaches a peak 2 weeks after conception then rapidly declines.