No risk = no reward. If you don't ask, whether you're a guy or a girl, you're missing out on wonderful possibilities by letting the opportunity pass. Don't wait and expect the other person to make the move, what if they're just as hesitant about it as you? Then both of you will be in agony for, potentially, months, pining needlessly about it.
Anyway. My girlfriend and I met at school in first year, we were in the same history class with one another all year, we spent probably november-christmas break, and january-march eyeing each other from across the lecture hall. When we finally got to talking, it turned out that we had absolutely everything in common, so we watched U2 in Boston and The Song Remains the Same the next afternoon. It wasn't until after we had kissed each other for the first time that we asked 'so... I guess we're "going out" now, or whatever'. In fact, due to crazy scheduling, we were together for about 3 weeks before we actually 'went out on a date' or whatever. Been together ever since, anyway, a year and 10 months - which would be something like two and a half years if either of us had actually bothered to come within 5 feet of each other and say 'hi' during that time. I'm very lucky to have not missed the boat, so to speak.