I have a similar question and here is some brief background info.
I met a cute 21-year old girl on Tinder and went on
4 dates with her over the course of 3-4 weeks. For
date one we went for coffee and got her back to my place. I started touching her and at the end went for a kiss, she turned it down saying "not yet". For the
second date, we cooked dinner at my place and kissed several times, but she resisted my advancements. But she did say she wanted to see me again. For
date number three, we watched a movie at my place and again kissed several times, much more passionately now. I got her shirt off but hit a wall after that, she basically saying it's too early for something more. I persisted a few times, even touched her down there from the top of her trousers, but could not get further than that. I made no big deal out of it and we even made vague plans for the next date.
So for
date number four we had coffee at my place in the evening, then we went out for a walk in the park/woods when it was dark. We sat on a bench, talked and kissed. Then we came back to my place again to have some ice cream. It was getting really late at that point so I suggested a massage at my bed to which she agreed. After that she couldn't resist my advancements no more and we finally had sex for the first time. It was not that great as I was tired already and I'm pretty sure she didn't orgasm. We still had some cuddling after that and decided to get some sleep.
So the next morning we got out of bed pretty quickly. She wanted to go to the shower so I invited her to shower with me, an offer which she surprisingly turned down (this was the first red flag for me). I said "alright" and after we were both done with the showering we decided to get breakfast from this diner close by. We still had some pretty interesting conversations over the breakfast after which we kissed goodbye (we both had other plans for the evening). But this whole post-sex day my gut was telling me that something was a bit off about her. I sensed that her enthusiasm was a bit faded in her kisses and everything. It was Sunday then.
The whole following week (specifically last week as I'm writing this) she was away working at her hometown which is far from where I live. I contacted her 2-3 times during that week. She texted me back, sometimes with long replys, but interestingly was quite vague about the topic of setting up the next date. I then presented two choices for this week, Monday or Tuesday, and she said Tuesday is fine for the date this week. A few days of silence went by then after the agreement.
So come this Monday I got a text from her saying: "
Hello!
I have to be boring now and ask you if we can move tomorrow for a different date? I have so much planning to do now with my upcoming internship that I really can't seem to make it tomorrow 
"
I replied: "
Yeah sure, no pressure! Get your things sorted out and let me know what date works better for you! 
"
To which she: "
Yeah
I also need to get my sleeping habits back in order
My autumn holiday was not so much a holiday for me"
Then my last reply: "
Yeah mine neither
Luckily I'm free this week."
So no counter-offer and haven't heard from her since. How long should I wait before trying to set a date again? I was thinking of waiting 2 weeks and if I don't hear from her, I'll text her something along the lines of what I read in some article here: "Hey there! School still keeping you busy? I was thinking of catching my breath this week: just relaxing and eating chocolate the whole day. Wanna join me?"