Re: how to tell......
Hey buddy, I reckon that two things might have happened:
1. She feels awkward now that you two have slept together and she's not really sure where you stand. This is more likely if she is a long time friend as opposed to someone that you recently met. In this case, there is obviously attraction however, I don't think that she's interested in an LTR at the moment.
2. It was just a one time thing, and she's cool with where you stand. Doesn't really explain why she's seeing you less but, hey, people do weird things sometimes!
I don't think that she's seeking attention but, I don't really know your guys' background. Just keep your Alpha frame, and you'll be fine!
"It ain't about how hard you can hit. It's about how hard you can be hit and keep moving forward"