Hi, I Took A Pregnancy Test Last June Which Came

Hi, I took a pregnancy test last june which came positive and started feeling symptoms of pregnancy. I also had spotting for a whole week accompanied with abdominal pain. I went to an OB-gyne for a checkup. she told me that she cant hear a heartbeat even though I am suppossed to be 3months pregnant. after a week I tested again since I wasn't feeling very well. It came in negative. And from then I was always feeling bloated, has urge to vomit, pain in the abdomen during bowel movements, sometimes constipation or diarrhea. I am worried