Hi. Thanks for your query and an elucidate history. To clear one thing:: testicle can never have a strain-- due to its anatomy. You could have strained the abdominal muscles the extension of which goes into the scrotum. This can have the referred pain in the testis, Another reason can be partial rotation / torsion . Please get this checked by a Surgeon or an Urologist. Get ultrasonography and color Doppler done to confirm the clinical findings by the Doctor. Till then :: Stop strenuous exercises Give scrotal support.