Might help if I add a photo!

Maybe and maybe not. Without a visible node, it's hard to say for sure. But stranger things have happened. I do know someone here that told me that whenever a leaf breaks off of his hoya, he sticks it back in the soil with the mother plant. I think he reported about 60% success that these create new vines.

And they used to always say those single-leaf sweetheart hoyas (kerii) potted alone never could grow a vine. But I have sure seen an awful lot of people disprove that.

So all you can really do is wait and see. Maybe talk to it daily and encourage it!