"Can we not do this?"

Yesterday I was escalating with some girl. We were on my bed, she was staring at me, our noses were touching. We brushed lips several times, and she would playfully say shit like "you're so forward".

But then she said "can we not do this?" and I immediately backed off, although physically she still seemed really receptive. It sounded a lot more...serious...than a common playful "no" and I didn't know if she intended it that way, but I wanted to err on the side of caution.

Do you think I did the right thing?

Edit: I don't know whether I should've backed off, or kept escalating. If I just looked at her actions instead of her words, all the lights were green.