Still salvagable for sure. Just stop worrying. Seriously, she seems interested enough to steer clear from LJBF. Quit labelling date/no date in your head. Every moment that you spend with her, you need to amp up the energy to "I want you." If you start thinking in your head, "I want you" instead of "I don't want to hear LJBF" then you positively influence your body language and aura to that of a MAN and not a friend. Just like thinking "I don't want to hear LJBF" is negative energy, so is worrying. QUIT WORRYING. Sure, it's ok to be unsure every so often, but get out of that rut ASAP if it creeps up.
Everyone's got it spot on with their advice. Have you started negging and kino? Seriosly, if you have not, now's the time to shine. Bring out the DJ and start letting her SEE and FEEL what you want, and make her want you.
Some ideas: next time you guys are at the gym, chat it up only a little. Spend most of your time WORKING OUT cause that was your mission at the gym. Every so often, use eye contact to your advantage. You shouldn't be hanging around her at the gym, cause she wants to work out too. The best part of the gym is guys will always go up to HBs and try their game. You sit back, notice the guys doing this, use your eye contact with a smile. Lock it on for a bit, and let her break with while she's getting hit on. You can even add some C+F by playfully winking during the chump session. Return to your program, and she'll be thinking of you while other chumps are AFCing her.
In class, manonfire got it spot on. If she's there before you, randomly sit next to her and not. In fact, if you randomly sit next to another girl and game it up with her even better. Now you got the jealousy factor on your side.
From here on out, I'd definitely tone it down.