Will strep test show positive at first sign of sore throat? Symptoms started less than 24 hrs ago, got tested, nurse said test negative. I often get strep.

The rapid strep test. Can be falsely negative 30% of the time, meaning you have the disease but the rapid test failed to pick it up. That is why many docs will send a culture. But even so, if you know you were exposed to another person who tested positive for strep pharyngitis, the guidelines say to treat regardless of what the rapid test shows. In that case many elect not to send a culture because it doesn't affect Tx.