Facebook "I cant see my friend on facebook"?

Now this is my problem, I cant see my friend online on facebook but others can. Two of my friends says that she is online right now but I cant see her on my chatbox. I can see my name on her friendlist and I can open her profile. I don't know if im deleted as her friend or am I blocked or its just that she click a setting that will make her appear offline to me. What should I do to know what exactly she did? I want to make sure what she did so that I can approach her in person and ask her why she did that. Im totally confused since yesterday we have a chat and I sort of confess my love for her =( now i cant see her online but others can. Wth? what should I do? am i really blocked,unfriend or what? pls help