post microfracture problem

I'm 21 and dx with ocd requiring microfracture on left knee. procedure was done without complication 5 days ago and was discharged to home without crutches or cpm.  only instructions where elevate+ice and daily aspirin.  my knee will not bend..I try but it just feels as if the clot is preventing my knee from moving. I'm in a lot of pain, my doctor advises me that it should come around but I am very leery... Any idea why my knee will not bend? Does anyone have any advice for any exercises I could do to increase range of motion? Any suggestions for me would be greatly appreciated, thank you.