Pain help !

I started getting pain on my right side on my belly,  and it went to the right side of my back also close to where my vagina is at ( well where hairs grow ?) anyways it lasted 30 minutes ! My belly did get hard but only the right side , where my baby is positioned. And it felt like if I pulled a muscle. But I know I didn't , now I'm all soar and idk what caused this pain or was it a contraction ? It hurts now, like if I had worked out my belly n only the right sides soar,