What Do Fluctuating Beta HCG Levels During Pregnancy Suggest?

I had gotten a positive pregnancy test on April 20th but started spotting on the 26th of April. My hcg levels have been increasing and decreasing for the past month it should be a 0 by now but still isn t. I ve also been having pain in my lower abdomen on the left side and upper left above the belly button when being pushed on or just sitting.Some nights i have to sleep with a pillow behind my back to get comfortable. I m also still having light bleeding off and on not heavy. I also still have a positive urine and blood test. I ve been to the hospital multiple times on different occasions and they said they didn t see anything in my uterus so I was told to go to a different hospital where there are obgyns that operate there and sad there was a possible small gestational sac in my uterus but wasn t quite sure. I m really confused no one seems to know whats going on like its a mystery. My doctor seems to think it may be an ectopic pregnancy and suggested a shot or can do surgery but not sure if it s best because there could possibly be nothing in the tubes. What should i do?Do I need a second opinion because I ve seen a Gyno? I m also a high risk. I feel like something is wrong.