I had something bad at exactly that time. I was coughing constantly. Still went to work. Went to the doctor, was negative for pneumonia and they said it's probably bronchitis. I had a lingering cough for 2 months. Lost my sense of smell for a while. It sucked but I could still function.

In March I had a covid test which was negative. Thing is now I wonder if it only shows up positive if you have an active infection?

I did. I went to the doctor and everything, testing negative for pneumonia so they said it wbronchitis.