Is she shy or scared of me?

It's been one and a half years, and I know that I REALLY should have gotten over this. However, it is not the case. There is a girl at my college who seems shy, but honestly I don't know. She would look at me until I have noticed her and she would quickly turned her head away or looks down or away and pretends like I didn't catch her then turns back to look at me, LOL who wouldn't when you(her) do it every time we crossed path. Funny thing is that this is still going on, which obviously makes no sense and it have gotten me to the point where I just have to research online for answers, yes I freak out trying to talk to her. She would look at me on and off, but she would not smile. When I first talked to her it was probably the weirdest start-off; however, she insist that I continue talking to her even after we got to her class, she invited me in to sit with her. During the conversation she didn't say much or laugh, but smile with open gestures to me although I felt the urge to leave, her body language was insisting that I stayed but after a while I left. Then one week later, as I was going to the student building, I happened to see her and before I got close, she got up with a terrified expression and took off. Although she took off terrified to see me, about a few weeks later she walked in the student building and stared at me, and didn't looked scared at all, in fact she went to sat in front of me; however she wasn't facing me. We've talked a few times after wards, but it just seems to make the situation more awkward, not to mention the fact that now she tries to avoid me by fiddling with her phone as she walks pass me. Although she ignores me, whenever I don't know that she is around, she is always glancing at me and turns her head quickly whenever I catch her looking at me.

I need a good observation!