Quick question

Long story short

-New girl
-Took on endless amount of dates (3 months in)
-Good exchange on investment, we both ask each other out, she paid for my dinner a few times
-Had no problem setting up dates with her
- Got 1 lay in with her

I asked her for a dinner date, she was flaky so I pushed for an actual day, we scheduled for a specific day, later she said she couldn't make it. Waited a few days, asked her out again but told her "Im seeing you this week for dinner, let me know the day your off". She said ok. Haven't heard anything back in 5 days. She's acting different for some reason, should I just wait for her to respond back, ball is in her court. I have already made 2 attempts.

Either a busy girl or you've got competition... I'd say the latter.

If it's been 5 days, then you COULD try again - or just simply ask her if everything's OK (I'd almost advise you to do nothing, and to take someone else out instead)...

If you do ask again, and you get blown off, you may want to retain some of your pride and just leave it.

She'll come to you if she's interested.

Simple.

She met someone else. And it couldn't be anymore obvious.

Why only 1 lay in 3 months?

We were only friends before I did the lay, I wasn't really into her that much besides the company before the lay.
Oh well life moves on, If she does text back any advice?

It's time to PULL. You've been pushing all along, and she can feel it. She doesn't want this. It is unattractive to her.

Here's a nice way to handle this particular situation
"Cancel the dinner invite, change of plans : D enjoy ur week"

Although it would have worked much better earlier in the week obviously, can still send this out, the week is not over and she is obviously not going to be replying to the earlier texts.

It's a 'push'. She will start to wonder about you, what you're up to, what (or who) you're doing.

From there, freeze her out for a period of several DAYS, and do NOT reply to her no matter what she says, despite your almost overwhelming urge to return to "pushing", you simply do not reply no matter what. Then hit her up in a few days after that with a very laid back text as though nothing happened like "saw a crazy ass movie last night, hwo ru". If you are not going to follow what is in this paragraph then don't even bother sending the initial text out because it will all be for nothing without the freezeout.

At the moment the girl is disinterested.

So in any case, you need to start "PULLING" with this girl, and stop pushing.

This all assumes she has some level of interest in hanging out after the lay. But hell, this can GENERATE interest so it's usually worth a shot no matter what.

theres no need to cancel anything since we never set anything up