No. You think you've had it. Given the symptom and the history, you probably have had it, but the test results could still be wrong, and you might have had something else that brought on a cough. Still, if you're convinced you've had it and can't get it again, that's your lookout....
I'd been in a hospital to visit a sick relative and 5 days later developed a persistent dry cough which was confirmed as covid-19 a week later by a PCR test, so yes, I have caught the disease.
Which is a bit of a selfish attitude to take.I don't care if I get it again. Either my immune system handles it in the future or it doesn't. I'm not going to spend the rest of my life shutting myself away from society every time the clowns running the government send me a text message.