i have a sharp pain in my hip flexor, what is it?

[averie scott]

i play soccer & i do gymnastics. my hips always pop when i straddle. i have soccer every single day, & now ever since my last game, ill get a sharp pain in my left hip flexor. it usually happens wen i walk ill get a really sharp pain, then it will go away. but it happens randomly throughout the whole day. what is it?