I had an abdominal hysterectomy almost 3 months ago. for a few weeks now, my legs have been hurting below my knees when i sit or lay down. any ideas?

Hard one: It is unlikely related to the hysterectomy. I assume you still have your ovaries. If not and there are no contraindications, then i strongly recommend you initiate hormones. Increased pain on both sides that increases with sitting is difficult. Most pain increases with standing, not rest. See if you changed shoe types recently but that is a hard one.