Hi welcome to Healthcaremagic
After any injury
to testes, if there is severe pain
, and the pain increases on the movement of the testes, then it signifies that there is torsion of testes... but in your case that there is not much severe pain, only mild pain.. not to worry much... there is no torsion.. but in future if you get injured and severe pain, do not neglect, in case of torsion of testes , it needed to be operated within 6 hrs, otherwise there will be loss of viability of testes... genitals maximally grow till the age of 21 years...
Hope i have answered your question