Thanks for your query. Based on the facts that you have posted it appears that you have either partial torsion of the left testicle or acute epididymitis
However final diagnosis can be confirmed only on clinical examination and ultrasound
scanning of the scrotum.
Please go ahead and consult qualified Urologist
as planned. The further treatment will be decided by him . In the mean while take broad spectrum antibiotic along with anti inflammatory drug like Diclofenac