Pain on left side of groin. Its a sharp pain when I stand up after sitting.

Groin pain. This may be a ghost to chase. Causes may range from groin hernia, more common in males to groin pull (usually there is history of groin injury). I've had patients with unidentified groin pain despite comprehensive work up. I suspect some anatomical variants of the area that predispose certain folks to having groin pain related to position change. But before you do need a work up done.