PREGNANCY OF UNKNOWN LOCATION

I've been to 4 ultrasounds and they still haven't located a baby! My levels are rising but not at the rate they should! I'm not experiencing any pain just stress!! They've checked my tubes and ovaries and nothing! I'm going to my last blood drawing and ultrasound on Thursday before they give me the shot to end the pregnancy! My levels were 1880 last draw. Has anyone experienced this?! And if so what was the outcome??!