I Am 73 Years Old And Had Left Hip Replacement

I am 73 years old and had left hip replacement surgery six weeks ago. Three days after I returned home getting into bed I cracked a bone near the hip replacement. Doctor said it would heal on its own. Two weeks later it should it was healing. I was doing well but the past few days I am in terrible pain on the left side along my backside. What can be wrong or am I still healing