First secondary transfer

So I'm a relatively new home brewer and Friday I did my first secondary fermentation transfer.

I had a couple of concerns. First of all my brew seemed to have a lot more activity early and then die out very fast. Within 12 hours it was bubbling extremely rapidly and by day 3 I had almost no visual activity. Is this something I should be concerned about. I just feel like I usually have a much longer period of primary fermentation.

Once I transferred to the secondary I had a small amount of activity for a couple more days. There are no bacteria that I can see and my taste test went ok.

It could be slowly fermenting down just a little bit more, or it could just be releasing some CO2 out of solution. Pretty normal either way, because the racking process stirs things up a bit - especially if transferred to secondary after only a week or less.

Visual activity doesn't mean much - just that the yeast doesn't want you to see what its doing. Trust your hydrometer.