Went to the ortho today and he wasn't able to tell me definitively what it was, though he leaned towards cyst. Went over to the hospital to have an ultrasound which at least revealed that it's not a clot. Still, the clock is ticking and I won't find anything out until tomorrow. Additionally, he didn't seem terribly optimistic that something effective enough to allow me to run regularly could be done quickly. Fuck me.