Hello,
Thank you for your query at DoctorSpring.com
It certainly seems related to your lifting weights. You should avoid physical exercise for few days and wear scrotal support. In addition, you can take a pain killer for few days so that the inflammation settles down.
If your pain does not settle down even after 4-5 days then you should get yourself examined to rule out hernia.
Feel free to discuss further,
Take care
Sincerely
Rajiv Goel