Tri-Lo Sprintec

I have finished my fourth month while on Tri-Lo sprintec, and my doctor said this wouldnt be a side effect that i would have. The sides of both my knee caps are swollen and feel bruised. I asked my mom what it could be and she said that it could be from bad circulation. Though im not much of a couch potato, im not super active, but this is the least common side effect i have ever heard from taking "the pill." Have any of you ladies had this?