Hi Myrth,
Hard to tell from a few lines whether she is being "sincere", testing you or totally bullshitting you… But let us not be paranoid and give her the benefit of the doubt. Even if we assume she is “sincere”, she is too much in control to my taste… she cancelled once and ran away upon receiving a message after you go kino? What the hell… I find that disrespectful…
OK… you know what? Let us be even nicer to her (but I am afraid we are crossing the AFC line honestly): she has a boyfriend and might simply try to hide her beginning affair with you (which btw also means the other dude means more to her than you, at least for now

). Even in this situation you better get back in control… You have done everything you could man… I dont know if you did it well, but you did…
So you know what you have to do now. You know it deep inside and you even wrote it: wait for a while. Stand-by until she gets back to you… At that stage I would not push any further: that would look needy and you dont need that because that would give her even more control and you won't get her this way… Be the cat, not the mouse!
My best advice? Until she comes back, get back to yourself and go for other girls… She’s getting laid elsewhere so why not you? For real. Do it without hatred or frustration... That is not a revenge, it is a normal behaviour for someone who respects himself! Be ready to lose her and move one… But dont make her a one-itis!!!
My two cents and first post here, hope it helps. You may wait for other’s advices too
Best of luck PUA!