If an ACL is completely torn, is surgery mandatory?

Or not? What are the advantages and disadvantages of having surgery v. not having surgery? I was told the ACL will not heal itself due to a lack of blood flow to that area? If I need surgery, I want it, but I am being told to wait 6 weeks (already waited 4 weeks on MRI results) and see what happens? They're sending me to PT for mobility? They said I may not need surgery that I could be fitted for a customized brace for active wear? I want to be as close to normal as I can - not stuck with a brace because an HMO wants to cut costs. I was told that when people tear their ACL they are sent to surgery immediately or within 2 weeks - what's true? I also have an MCL tear and may have a meniscus tear (MRI was inconclusive).