Suggest Treatment For Knee Pain Due To Torn ACL

Hi, A month back I was injured in a bike accident but there was no pain on my knee. Gradually the pain started growing and I consulted a Orthopedic. He gave two types of tablets and I was feeling ok. But the pain came back and the doctor suggested for an MRI. I got the scan done and it says" ACL complete Tear". Now the doctor suggested me to go with physiotherapy exercises for about a month and if the same pain sustains then for a reconstruction(surgery). My question is can I regain the muscle in this one month period of time with these exercises and my daily regular schedule? or do I have to take a complete bed rest?