[PK-EK]

I'm not going to tell you if you were a rebound or not; there is no point
OP just needs to know what to do know.

Give it time.
I went through a similar thing. (still on going actually)

I wow'd a girl that just got out of a relationship and i confused the shit out of her; even up to this day, she is unsure of her feelings.

Give it time, thats all you can really do.
Time will give you the answer either it be good or bad.
Over time she might realize that her feelings towards you are real.
Over time she might realize that it was just impulse.

Just tell her your feelings once (i think you already did that)
and wait.