Was I pregnant? Help

My boyfriend and I have been trying to conceive for the last four months. I could have sworn I was pregnant because I was having all of the symptoms. I thought I was just sick though. I had extremely bad nausea at night time, tugging sensation like I did 1000 on the day that I ovulate, but I didn't exercise, missed period, peak in temperature, faint positive pregnancy test and more. When I went to go follow up with my obgyn they confirmed that I wasn't pregnant even though the pregnancy test at home showed I was and with all of my symptoms as well. Could I have had a miscarriage and didn't even know it? What do you guys think is going on? I know I wasn't imagining all of this either.