Could I be pregnant?

Okay my lmp was June 19. I tested for the first time at 9 dpo and got a faint positive. Continued testing each day and kept getting positives but never as dark as the control line. I Assumed I was pregnant and scheduled an ultrasound, told my family, etc. I was concerned because the line never got darker though. But also never got lighter. I had to be on progesterone supplements during my first trimester of my first pregnancy so I requested blood work to test my levels to see if I needed it for this one ( also because I was concerned that my bfp wasn’t getting any darker) next morning ( at 4 weeks 3 days l) I start my period. So sad. I cried all day. About that time the receptionist called and said my blood test was negative and that I was never pregnant. I told her I had about 15 positive tests and she said they were false negatives and that there was no hcg or progesterone in my body. I assumed it was a chemical pregnancy and went about my day. But the weird thing is that the period only lasted 48 hours. I might go buy another hpt tomorrow because I can’t resist. Has anyone ever had anything like this happen to them? A pregnancy without or with extremely low hcg? Maybe I’m just in denial.. thanks!