Hi, My Son Is 15, 125lbs 5'8. He Came Home

Hi, my son is 15, 125lbs 5'8. He came home from school a few days ago claiming he thought he had pulled a muscle in his groin area while skateboarding on a halfpipe. I figures it was just that, no biggie, we iced it and went about our day. This morning he came to me and showed me a pretty big bump on his right inner hip/groin area just outside the pubic bone. It is hard, and only hurts when he pushes on it. Can you please help? Can this be a hernia?