Write an article based on this summary:

Consider whether any of the risk factors for ectopic pregnancy apply to you. Have your -HCG levels checked in a blood test. Undergo a transvaginal ultrasound. Allow your doctor to perform a diagnostic laparoscopy.
If you are experiencing any of the symptoms mentioned above, you also need to consider if you fall into the high risk group of ectopic pregnancies. Certain factors increase a woman's likelihood of experiencing an ectopic pregnancy. Generally, women who have had an ectopic pregnancy in the past are more likely to experience such pregnancies in the future too. Other risk factors include: pelvic infections (sexually transmitted infections), multiple sexual partners (as this increases the chance of unknown STI's), fallopian tube tumors or abnormalities, previous abdominal or pelvic surgery, having an IUD, endometriosis, or smoking. Also, if a woman has had "sterilization" (also known a "tubal ligation" surgery, when her "tubes are tied" in an effort to prevent future pregnancy), although this is normally very successful in preventing pregnancy if one were to become pregnant the risk of it being an ectopic pregnancy is notably higher. This is the first step towards the diagnosis of an ectopic pregnancy. -HCG is a hormone that is secreted by the developing embryo and placenta, so it rises as the pregnancy progresses and is a more definitive (and reliable) form of pregnancy test. If the -HCG level is above 1500 IU/L (often between 1500-2000 IU/L is suspicious), but no pregnancy is seen with ultrasound, doctors will worry about you having an ectopic pregnancy. This is because the -HCG levels are normally higher in ectopic pregnancy than in normal intrauterine pregnancies, so it is certainly a cause for suspicion. If an ectopic pregnancy is suspected due to your -HCG levels, your doctor will follow this up with a transvaginal ultrasound to see if she can visualize a pregnancy, and its location. These ultrasounds can detect 75-85% of ectopic pregnancies (the growing fetus will be able to be seen on ultrasound in that percentage of cases, which confirms its location). Note that a negative ultrasound does not rule out an ectopic pregnancy. A positive ultrasound (one that confirms the presence of a pregnancy in the fallopian tubes or elsewhere outside the uterus), however, is enough to make the diagnosis. If the ultrasound is negative (i.e. inconclusive), but the -HCG level is high and your symptoms are enough to concern your doctor that you may have an ectopic pregnancy, your doctor will likely recommend a "diagnostic laparoscopy," which is a simple surgery with very small incisions where they can insert cameras into your abdomen to have a clearer look. If your blood tests and ultrasounds seem inconclusive, and an ectopic pregnancy is still suspected, your doctor may perform a diagnostic laparoscopy to visualize your pelvic and abdominal organs internally to look for the spot of implantation. This procedure usually lasts for 30 minutes to an hour.