The usefulness of h CG measurements decreases as the pregnancy progresses.
In very early pregnancy, the baby is too small to see on an ultrasound, so h CG tests may be the only tool for evaluating how the pregnancy is developing.
It could be that you ovulated late in your cycle that month and a follow-up ultrasound will show that the pregnancy is viable but simply not as far along as you and your doctor originally estimated.
If you are having miscarriage symptoms (such as vaginal bleeding and abdominal cramping), it's a good idea to call your doctor to get an answer to the question that is likely running through your mind: "Am I having a miscarriage?"In order to figure out whether you're miscarrying, your doctor will probably use some combination h CG blood tests, an ultrasound, fetal heart scanning, and (sometimes) a pelvic exam.Your doctor will decide which tests are most appropriate for your situation to tell you whether or not you're miscarrying.Diagnostic tests for miscarriage rarely offer information about the actual cause of the pregnancy loss, but because vaginal bleeding and cramping are not always caused by miscarriage, the tests will help your doctor determine what is happening. Human chorionic gonadotropin (h CG) is a hormone that is produced in your body exclusively during pregnancy.
By the time a heartbeat and gestational sac are clearly visible on ultrasound, an ultrasound is much more useful for determining whether you're having a miscarriage.
Ultrasound machines use sound waves through the abdomen or vagina to get a rough image of the gestational sac and developing baby in your uterus.