I Had Knee Surgery 8 Weeks Ago, The Knee Is

I had knee surgery 8 weeks ago, the knee is coming along well but since I've had pain the calf of my leg plus pain in the thigh and hip. The last week I've got so tired and the last three or four very short on breath when I do anything. Also coughing at night. Might this be related to surgery? Also feelvery lightheaded.