Did my spell work even if I didn't do it physically?

Basically, the dog of a girl I know ran away during a thunderstorm. After a couple of days the dog hadn't returned.

I tried to help them look for her but after those first couple of days I thought I'd try a spell. I'm new at spell work, I've been reading and studying a lot. I haven't done a ton of spells but I the ones I've tried have always worked to some extent.

I first tried to look up spells to help find lost dogs/animals but I didn't find anything. Then I remembered reading about how the spells we create can be very powerful. It was already late, so I went to bed, closed my eyes and meditated on it, putting to work the things I've been reading lately. I made a very detailed spell/practice, all parts of it with meaning and I was really happy with it. 

I did the whole work besides actually doing the spell physically. I meditated, I thought about my connection to the dog (I never met the dog but thought about all the strings and paths that connected us), I held my intent in my heart and after I "built" the spell, I thought about myself doing it. I was filled with hope.

I never ended up actually doing the spell because the next morning I woke up to a message that the dog came back!

Ever since, I've been puzzling in my head if the spell may have worked in some way, even though I didn't physically did it, or if it was just a coincidence. Not that I need it to have worked, I'm just glad the dog is back in her home, but just to puzzle things in my head about how spells and witchcraft work.