I have never heard of someone seeing a psychiatrist or therapist and not getting any diagnosis at all.

I have twice. Two different therapists, after three sessions, told me I was well adjusted and experiencing normal emotional response to stressful events. One told me she saw no reason to schedule additional meetings. The other said I could keep visiting him but he couldn’t bill insurance since there was no diagnosis.

That said, this story is unique among everyone I’ve ever spoken to about it.