@sharonednaramsey @lvnl gave you great advice. In my bronchiectasis journey of over 8 years, I have been "positive" for a number of mycobacteria and other infections in one culture, then they never showed up again.
After reading your discussion of handling the specimen, you may have had a "contaminated" sample.

This is a good lesson for all of us - sputum for culturing should be spit directly into a newly unsealed specimen cup, promptly capped, and delivered to the lab according to your provider instructions. In my case, I have been told to refrigerate if it will be 4 hours or longer before delivery.

My pulmonologist keeps me supplied with cups, with standing orders for the lab to give me replacements every time I turn in samples.

Do you typically spit directly into a specimen cup?