Pulled muscle in leg i think?

i was puttin a not to heavy amp in my truck and i was really gettin a good strectch puttin it in the bed and it felt like i stretched to hard and hurt in between my joint where my leg and groan meet do you think i pulled a muscle or hernia or tore somethin what should i do to relieve the pain which the pain is not to bad just feels like i pulled it too hard or something