Need advice for this girl...

I'm hardly out to anyone, except for a few people.
I study at a university, and in the past winter (January - May 2012) semester, there was a girl I was completely crushing on. She asked me to be partners in a project, and I'm usually really shy but we did a lot of things together after this project. We chilled in her dorm, I gave her dating advice for guys she was crushing on (I was sooo jealous but I sucked it up to be a good friend), participated in some events together, etc. Then, we made it so we would at least have one class together in the Fall.

I have no idea if she is straight or if maybe she might be bi, and I don't know her opinion on LGBT. I'm terrified of telling her I like her because of everything we've done together (I helped her put laundry away a few times, which is kinda akward... being wrist deep in her underwear drawer...)

So I don't know what to think or do. I think I'm being hopeful she might be secretly bi and like me, but I might just be reading too deeply into things she does (a lot of hugs, punching me when I tease her, inviting me to her dorm a lot of the time and pouting when I have to leave). Worst of all I don't want to tell her and then ruin whatever friendship we developed.

As a side note.. she also in some lights reminds me of an ex. I don't know if I like her because she reminds me of my ex, or if I like her despite the fact she reminds me of my ex.

Any one have advice?