Selena Gomez Goes To Emergency Room

Sources close to the singer tell us ... Selena has been suffering from a sore throat lately ... and yesterday morning she thought she might have strep, so she decided seek immediate medical attention.

We're told Selena had been suffering from symptoms Sunday ... and had to end a recording session early due to the pain.

Also, Selena's stepfather has been suffering from bronchitis, and she thinks she may have been exposed to something contagious.