second chance or moving on

[confused696969]

I have been doing NC with my ex for 3 weeks now. I told her not to contact me, and i wasnt going to contact her (maby not a good idea telling her i was going to do that, i shouldve just done it, but too late now) because since she needed her "space" i didnt want to know what was going on and wonder if shes with anyone else and all that jazz because it was tearing me up inside just thinking about it, and if i knew of something actually happening with others then i dont know what would happen to me. I am planning on holding out until the xmas/new years holiday and confront her one last time, becasue i am definately not over her, and still want to work things out and get back together. I figured i would give her some sort of ultimatum (i dont know of any other word or phrase to describe it), that she needs to make a decision soon, because i have to know whetehr we can work it out or not. Being causght between not knowing if we will, or if we never will is driving me nutz and making NC so damn hard, so I thought i would give her this ultimatum, and if she finally says no i can get over her. opinions on this or this approach, has it worked for others, do second chances even work in the end, or is there other approaches i can do to get a definitive answer so i can move on (with or without her if need be)??