My ex and I was together for 5 year and broke up under strange circumstances and the wrong reasons. She was being pressured from her mate. Two week after the break up she got into a relationship with a guy she barely knew who was coincidently friends of the mate who pressured her and they have just recently ended days before I was going to be going to the army. She asked to meet up with me because she wanted to see me and when I did she asked me not to go in the army and said I'm a big part of her life and that she doesn't want to be in a relationship and that loads of people still have families and stuff in the army and kept saying she can't promise me anything but she thinks I shouldn't go in. She said to me she can't explain what she feels inside and she doesn't know what will happen in the future. 

She told me she wants three weeks to sort herself out and doesn't want any contact only the date I'm going in the army and even after the three week she can't promise anything and doesn't know what will happen. I am so confused and don't really don't understand what's going on. Why three week and why make a big fuss to stop me going in the army but yet she said she can't promise anything and doesn't want to be in a relationship we have been over for three month so why all this now when for the past three month she been distant and hasn't seemed bothered.

I don't understand any of it. Can anyone help. 

I think its plain she is keeping her options open and wants you to wait while she mulls them over.

Follow your own path for your own future well being, and don't wait for the confused to be unconfused. She dumped you, and you are still dumped, and there seems to be NO confusion with that.

She can write you in the Army you know, if she gets her head together.

Who knows what is going through her mind, maybe she still cares and is afraid for you. Concentrate on your work, career and do well in the army. Not if, but WHEN you come back, if she wants to be with you she will find you.