Break Up & Divorce

I asked her out, she said she'd let me know, but hasn't yet.

I've known this girl since last fall. She's very shy and quiet yet has always given me signs she likes me, as in constant smiling, long gazes, giggling and so forth, yet we rarely see each other. We've been teasing and flirting via texting for several months. I asked her out a couple days ago at work if she'd want to hang out this Saturday, she said she'd let me know. However she seemed kind of indifferent and I have this feeling she'll forget or even want to get back to me.

If she doesn't contact me should I let it go or get in touch with her in a couple days and bring it up again?
Updates
+1 y
Okay contrary to what some fo you advised, I contacted her and in mid conversation I asked her again, she didn't think she'd have the time due to a bunch of assignments and exam studying due in a few days. I believe she's being honest as we've talked about her classes in the past. No harm was done asking, and we still conversed after the fact. No desperation and no pushiness on my part! Thanks for answering!
I asked her out, she said she'd let me know, but hasn't yet.
Post Opinion