Re-fermenting in the Bottle?

I took yesterday and today off in order to apply for and collect my immigrant visa, which I did this morning. After filing my application yesterday, I pottered off home to decide what to do with myself for the rest of the day.

Now I must confess that I have a bad habit, I like to check on my homebrew regularly - well ok then, every time I get home, I pop my head into the room it is kept in just to make sure nothing has gone awry. Yesterday I picked up one of the bottles and noticed a little foam on top of the beer so of course I checked the swing top to make sure it was secure, which it was.

I had a quick look at the other bottles in the batch, and all of them seemed to have a little foam on top. This morning though most of the foam had gone and things were back to normal.

I am assuming that the priming sugar was simply being eaten by the remaining yeast in the beer, and that nothing drastic has happened.

Any thoughts?