Let's call the girl Susan

Context (will elaborate if someone asks):

We are college students. First met Susan at her house when visiting her roommate, didn't talk to her much at all, passed out drunk on her couch, she gave me a ride home the next day. Few months later (last week) she randomly saw me at a restaurant/bar, enthusiastically comes up and we chat a few seconds, invites me over to her place sometime, forgot to get her number

Here's how our text convo went:

[The next evening]

Me (on facebook): Hey, it was a nice surprise running into you again. I'm gonna have to take you on that invite one of these days, but I didn't get a chance to get your number last night. Mine is xxx-xxx-xxxx. What's yours?

[A day later in the morning]

Susan (on facebook): Yes same to you!! You'll definitely have to come over and see all of us

Susan (on facebook): my number is xxx-xxx-xxxx

[Later that night, the following texts happened over a span of 3 hours, I always waited a while before responding]

Me: Want to come over to my place on a weekend?

Susan: Who is this?

Me: [My name]

Susan: Oh yes we should get together with all the roommates!

Me: Awesome! How does Saturday sound? We can drink and maybe play mario kart or something. I don't know if my housemates will be here or not though

Susan: Well this weekend may not work for me because my best friend is visiting

Me: I meant next weekend. I'm going back home tomorrow

Susan: I'll actually be in [State] next weekend! :(

Me: Haha well since someone is so busy, you pick

Me: Actually it doesn't have to be a weekend, you free on weeknights?

Susan: Yeah mostly free! I can let you know when I am because my schedule is kind of crazy

Me: Even though I'm free most days after work, you'll probably pick the one day I'm not haha

Me: We shall see though, let me know tomorrow before I make other plans

[Two days later]

Me: So when are you free girl?

Now, 4 days since my last text, I haven't heard anything from her. What do you guys think of this and what should I do?