What is a beta?

Your Beta is the blood test you take to confirm your pregnancy.  The test measures the amount of HCG in your bloodstream.  In very early pregnancy, the numbers might not be very high but they should quickly increase.

A single HCG level can't really tell you much about your pregnancy but watching the increase over several days is one way of measuring the viability of the pregnancy. 

As this site demonstrates, there is a large variation in beta numbers in a "normal" pregnancy.  Caution must be used in making too much of HCG numbers and your Doctor is your best source of advice about your own pregnancy.  An ultrasound at five or six weeks of pregnancy can better predict a good pregnancy outcome than any number of beta tests.  As a note, you won't expect to see a gestational sac or the fetus until the HCG level reaches at least 1,200 mIU/ml.   And you probably won't see a heartbeat until that level reaches at least 6,000 mIU/ml.