QUANTITATIVE HCG :

If your urine pregnancy test is positive and the situation is low risk, there is usually no reason to check a quantitative hCG. However, if there are risk factors for miscarriage or tubal (or ectopic) pregnancy, serum hCG values can sometimes be helpful.

Simply defined, an ectopic pregnancy is one in which the fertilized egg does not make its way all the way to the uterus, but comes to rest in one of the fallopian tubes. The fallopian tubes are the passageways that connect the ovaries to the uterus. They are not as stretchable as the uterus and are not able to provide the nutrients necessary to maintain a pregnancy. When an egg mistakenly implants in one of these tubes, it typically results in a miscarriage, and in some cases, a breaking of the tube (called a ruptured ectopic). Ectopic pregnancies often cause pain, and in some cases internal bleeding. Most of the time, a tubal pregnancy can be diagnosed and treated before it becomes serious.

Risk factors :
Certain conditions in a person's past can increase the chance for an ectopic pregnancy. In general, about 1 out of 100 pregnancies is outside of the uterus. It is more frequent in women who have had prior ectopic pregnancies, or who have had damage to their fallopian tubes. Tubes can be scarred by infection, surgery, or endometriosis. Common infections that can cause damage include gonorrhea, chlamydia, and pelvic inflammatory disease (PID). Other infections, such as herpes, HPV (warts), HIV, and syphilis, are not thought to cause tubal damage.

Women who become pregnant while they have an IUD in place also have an increased chance for ectopic pregnancy, as do women undergoing fertility treatments.