What happened?

Last month, I had my first positive pregnancy test. Through this app, I determined I was 5 weeks. Two days later, I started bleeding. I went to the doctor the next day, and they did a urine test, which resulted negative, and then a blood test, which showed my Hcg levels at 1.2. My doctor never gave me a clear answer on what may have happened. She just said I wasn’t pregnant. I’m having a hard time dealing with this and moving forward- was I ever pregnant? Was it a false positive? Did I miscarry, or did the egg not implant? I’ve been ttc for 6 months, which I know isn’t long at all, but we desperately want a baby. I guess I’m just venting, looking for someone who’s maybe experienced the same thing.