There are certain circumstances. You may requested to run a blood test in order to detect and quantify the exact level of HCG hormone in your body. For example, if you have been undergoing fertility treatment, you may want to know if it has been successful even before your period is expected. Accurate regular measuring of HCG is also needed if you are suspected to have etopic pregnancy. What is etopic pregnancy? Etopic pregnancy is a pregnancy that develops outside the uterus, usually in the Fallopian tube.
Using the method of ultrasound scan can be another alternative way of pregnancy testing. Scans are not performed routinely in very early pregnancy, but they can be useful if you are unsure of your dates, have a history of miscarriage or if you have symptoms or signs to suggest that you may have an ectopic pregnancy. Although there is little to see on the scan until about 10 days after you missed period, after this time it is usually possible to see the pregnancy sac in the uterus with a tiny fetal pole (a definite rectangular blob within the sac) and sometimes even a beating fetal heart.