Can you be more thorough please in outlining what's going on? We only have your verbal picture to go on and you've left enough holes for swiss cheese.
What sort of pain? Sharp or dull? Constant or intermittent? Numb or achy? Specific or radiating? Is it better in the morning or evening? hot or cold? standing or lying down? Does a warm shower make it better or worse?
Do you have the same issue in Baddha Konasana, Vrksasana, Trikonasana, Parsva Supta Padangusthasana, Parsvakonasana, Uppavishta Konasana, Janu Sirsaana? In fact do you have a yoga practice of any sort (you don't mention)?
Therapeutic issues need to be assessed and that assessment should be in-person. However when it is not in-person it is entirely dependent either on a) a complete guess by a stranger or b) a verbal Rembrandt from the person posting.