No Hcg but Pregnant...

Hi there..im new here and would like to share my story. Had unprotected during my fertile days and now I'm 80 days late with BFN. Definitely my first time going through this. Feel so pregnant with all symptoms and was really upset when docs didn't pay much attention during ultrasound. And was told no etopic or cyst found. I was told there's no way i can be pregnant with those negatives.But i do know some ladies who went undetected till about 23-27 later. BTW, I started taking folic acid since Jan and evening primrose oil since Mar (on/off). Wouldn't want to the vitamins to take the blame for this so for now, I'm still looking around for ans to my misery. Anyone here going through the same..?